Chapter XXXIV: Introduction (30)

2. _Lepas Hillii_, Leach. (Darwin, 'Lepadidæ,' p. 77, Tab. 1, fig. 2.)

L. valvis lævibus; scutorum dentibus internis umbonalibus nullis; carinâ à cæteris valvis, furcâ etiam a scutorum basali margine, paululum distante; pedunculi parte superiore aut pallidâ aut aurantiacâ.

_Hab._--In Oceano, pæne ubique.

3. _Lepas anserifera_, Linn. (Darwin, 'Lepadidæ,' p. 81, Tab. 1, fig. 4.)

L. valvis approximatis leviter sulcatis (tergis præcipuè); scuto dextro dente forti interno umbonali, lævo aut dente exiguo, aut merâ cristâ instructo; margine occludente arcuato, prominente; pedunculi parte superiore aurantiacâ.

_Hab._--In Oceano, pæne ubique.

4. _Lepas pectinata_, Spengler. (Darwin, 'Lepadidæ,' p. 85, Tab. 1, fig. 3.)

L. valvis tenuibus, crassè sulcatis, sæpe pectinatis; scutorum cristâ prominente ab umbone ad apicem, juxta marginem occludentem, pertinente; furcæ carinalis cruribus inter angulos 135° et 180° divergentibus.

_Hab._--In Oceano Atlantico, sept. et meridionali.

5. _Lepas australis_, Darwin. ('Lepadidæ,' p. 89, Tab. 1, fig. 5.)

L. valvis glabris, tenuibus, fragilibus; scutorum dentibus umbonalibus utrinque internis; carinæ parte superiore latâ, planâ, suprà furcam valdè constrictâ; furcæ cruribus latis, planis, tenuibus, acuminatis, intermedio margine non reflexo.

_Hab._--In Oceano meridionali.

6. _Lepas fascicularis_, Ellis. (Darwin, 'Lepadidæ,' p. 92, Tab. 1, fig. 6.)

L. valvis glabris, tenuibus, pellucidis; carinâ rectangulè flexâ, parte inferiore in discum planum oblongum expansâ.

_Hab._--In Oceano torrido et tepido, pæne ubique.

2. _Genus_--PŒCILASMA.

1. _Pœcilasma Kæmpferi_, Darwin. ('Lepadidæ,' p. 102, Tab. 2, fig. 1.)

P. valvis 5; carinæ basi truncatâ et cristatâ: scutorum dentibus internis umbonalibus fortibus: tergorum acumine basali truncato, margini occludenti pæne parallelo.

_Hab._ in Japaniâ.

2. _Pœcilasma aurantia_, Darwin. ('Lepadidæ,' p. 105, Tab. 2, fig. 2.)

P. valvis 5; carinæ basi truncatâ: scutis ovatis, margine basali per-brevi, dentibus parvis, internis, umbonalibus instructo: tergorum acumine basali perobliquè truncato.

_Hab._--In Insulâ Madeirâ.

3. _Pœcilasma crassa_, J. E. Gray. (Darwin 'Lapadidæ,' p. 107, Tab. 2, fig. 3.)

P. valvis 5; carinæ termino basali in discum parvum infossum producto: scutis convexis, dentibus internis umbonalibus nullis: tergis pæne rudimentalibus, vix carinâ latioribus.

_Hab._--In Insulâ Madeirâ.

4. _Pœcilasma fissa_, Darwin. ('Lepadidæ,' p. 109, Tab. 2, fig. 4.)

P. valvis 7; scuto utroque è duobus juxtapositis segmentis formato; segmento altero intus dentato: tergis brevibus, ter aut quater carinâ latioribus: carinæ termino basali in discum parvum angustum infossum producto.

_Hab._--In Archipel. Philippino.

5. _Pœcilasma eburnea_, Hinds. (Darwin, 'Lepadidæ,' p. 112, Tab. 2, fig. 5.)

P. valvis 3; scutis acuminatis, ovatis; ad pedunculum pæne transversè spectantibus; dentibus internis umbonalibus fortibus: tergis nullis carinæ termino basali in discum amplum oblongum infossum producto.

_Hab._--In Novâ Guineâ.

3. _Genus_--DICHELASPIS.

1. _Dichelaspis Warwickii_, J. E. Gray. (Darwin, 'Lepadidæ,' p. 120, Tab. 2, fig. 6.)

D. scutorum segmento basali duplo latiore quam segmentum occludens: tergorum parte inferiore paulò, latiore quam occludens scutorum segmentum.

_Hab._--In Archipel. Indico orientali.

2. _Dichelaspis Grayii_, Darwin. ('Lepadidæ,' p. 123, Tab. 2, fig. 9.)

D. scutorum segmento basali angustiore quam segmentum occludens; longitudine pæne dimidiâ: tergis bipenniformibus, margine crenato, spinâ posticâ, manubrio angustiore quam occludens scutorum segmentum.

_Hab._--In Oceano torrido, aut Indico, aut Pacifico.

3. _Dichelaspis pellucida_, Darwin. ('Lepadidæ,' p. 125, Tab. 2, fig. 7.)

D. valvarum singularum acuminibus superioribus et inferioribus vix intersecantibus: scutorum segmento basali multo angustiore quam segmentum occludens; longitudine ferè dimidia: tergis bipenniformibus, margine integro, manubrii acumine ad carinam flexo.

_Hab._--In Oceano Indico.

4. _Dichelaspis Lowei_, Darwin. ('Lepadidæ,' p. 128. Tab. 2, fig. 8.)

D. scutorum segmento basali angustiore quam occludens segmentum, longitudine ferè 4/5: tergorum parte inferiori duplo latiore quam occludens scutorum segmentum.

_Hab._--In Insulâ Madeirâ.

5. _Dichelaspis orthogonia_, Darwin. ('Lepadidæ,' p. 130, Tab. 2, fig. 10.)

D. scutorum basali segmento angustiore quam occludens segmentum; longitudine ferè dimidiâ; duorum segmentorum junctione calcareâ: tergorum prominentiis marginalibus inæqualibus 5: carinâ deorsum in parvo calyce lunato terminatâ.

_Hab._--(?)

4. _Genus_--OXYNASPIS.

1. _Oxynaspis celata_, Darwin. ('Lepadidæ,' p. 134, Tab. 3, fig. 1.)

_Hab._--Insulâ Madeirâ.

5. _Genus_--CONCHODERMA.

1. _Conchoderma aurita_, Linn. (Darwin, 'Lepadidæ,' p. 141, Tab. 3, fig. 4.)

C. capitulo duobus tubularibus quasi-auribus instructo, pone terga rudimentalia (sæpe nulla) positis: scutis bilobatis: carinâ nullâ, aut omnino rudimentali: pedunculo longo, a capitulo distincte separato.

_Hab._--In Oceano, pænè ubique.

2. _Conchoderma virgata_, Spengler. (Darwin, 'Lepadidæ,' p. 146, Tab. 3, fig. 2.)

C. scutis trilobatis: tergis intùs concavis, apicibus introrsùm leviter curvatis: carinâ modicâ, leviter curvatâ: pedunculo in capitulum coalescente.

_Hab._--In Oceano, pænè ubique.

3. _Conchoderma Hunteri_, Owen. (Darwin, 'Lepadidæ,' p. 153, Tab. 3, fig. 3.)

C. valvis angustis: scutis trilobatis, prominentiâ laterali non latiore quam inferior: tergorum parte superiore pæne rectangulè secundùm aperturæ marginem flexâ: carinâ valde arcuatâ: pedunculo brevi, in capitulum coalescente.

_Hab._--In Oceano torrido, aut Indico, aut Pacifico.

6. _Genus_--ALEPAS.

1. _Alepas minuta_, Philippi. (Darwin, 'Lepadidæ,' p. 160, Tab. 3, fig. 5.)

A. aperturâ non prominente, capituli longitudinis vix tertiam partem æquante: scutis corneis, pæne absconditis: longitudine totâ ad quartam unciæ partem.

_Hab._--In Mari Mediterraneo.

2. _Alepas parasita_, S. Rang. (Darwin, 'Lepadidæ,' p. 163.)

A. aperturâ non prominente, capituli longitudinis 2/3 æquante: scutis corneis: longitudine totâ ad 2 uncias.

_Hab._--In Mari Mediterraneo et Oceano Atlantico septentrionale.

3. _Alepas cornuta_, Darwin. ('Lepadidæ,' p. 165, Tab. 3, fig. 6.)

A. aperturâ parvâ, leviter prominente: scutis nullis: capitulo plerumque tribus, parvis, compressis eminentiis secundum carinalem marginem instructo.

_Hab._--In Insulis Indicis occidentalibus.

4. _Alepas tubulosa_, Quoy et Gaimard. (Darwin, 'Lepadidæ,' p. 169.)

A. aperturâ parvâ prominente et tubulosâ: scutis et prominentiis secundùm marginem carinalem, nullis.

_Hab._--In Novâ Zealandiâ.

7. _Genus_--ANELASMA.

1. _Anelasma squalicola_, Lovén. (Darwin, 'Lepadidæ,' p. 170, Tab. 5, fig. 1-7.)

_Hab._--In Mari septentrionali, squalis affixa.

8. _Genus_--ALCIPPE.

1. _Alcippe lampas_, Hancock. (Darwin, 'Balanidæ,' p. 530, Tab. 22, et Tab. 23, fig. 16-19.)

_Hab._--Littoribus Anglicis, molluscis condita.

9. _Genus_--IBLA.

1. _Ibla Cumingii_, Darwin. ('Lepadidæ,' p. 183, Tab. 4, fig. 8.)

I. (fœm.) valvarum marginibus lateralibus, et superficie interiore, cæruleis; pedunculi spinis plerumque annulis cæruleo-fuscis.

_Hab._--In Archipel. Philippino, et littore Burmah.

2. _Ibla quadrivalvis_, Cuvier. (Darwin, 'Lepadidæ,' p. 203, Tab. 4, fig. 9.)

I. (Herm.) valvis et pedunculi spinis sub-flavis; basali tergorum angulo, introrsùm spectanti, hebete, quia margo carinalis inferior longiùs quam mango scutalis prominet.

_Hab._--In Australiâ meridionali.

10. _Genus_--SCALPELLUM.

_Sectio † Carinæ umbone sub-centrali._

_Sectio †† Carinæ umbone ad apicem posito._

[_Sectio_ †.]

1. _Scalpellum vulgare_, Leach. (Darwin, 'Lepadidæ,' p. 222, Tab. 5, fig. 15.)

S. (Herm.) valvis 14, si rostrum pæne rudimentale includatur; sub-carinâ nullâ; lateribus superioribus inæqualiter ovatis.

_Hab._--In maribus Europæ.

2. _Scalpellum magnum_, Darwin. ('Lepadidæ Fossiles,' p. 18, Tab. 1, fig. 1.)

S. valvis probabiliter 14, sub-carinâ nullâ; laterum carinalium et rostralium umbonibus liberè (sicut cornua) prominentibus, dimidiam seu tertiam partem longitudinis valvarum æquantibus.

_Foss._--In "Coralline Crag Formatione," Angliâ.

3. _Scalpellum ornatum_, J. E. Gray. (Darwin, 'Lepadidæ,' p. 244, Tab. 6, fig. 1.)

S. (Fœm.) valvis 14, sub-rufis; sub-carinâ nullâ; lateribus superioribus quadranti-formibus, arcu crenâ profundâ notato.

_Hab._--In Africâ meridionali.

4. _Scalpellum rostratum_, Darwin. ('Lepadidæ,' p. 259, Tab. 6, fig. 7.)

S. (Herm.) valvis 15; rostro per-magno; sub-carinâ præsente; laterum paribus quatuor; pari superiore pentagono.

_Hab._--In Archipel. Philippino.

5. _Scalpellum Peronii_, J. E. Gray. (Darwin, 'Lepadidæ,' p. 264, Tab. 6, fig. 6.)

S. (Herm.) valvis 13; sub-carinâ præsente; laterum paribus tribus; pari superiore multùm elongato; pedunculi squamis calcareis nullis.

_Hab._--In Australiâ.

6. _Scalpellum Darwinianum_, Bosquet. ('Monograph. Crust. Foss. de Limbourg,' Tab. 4, fig. 1-5.)

S. carinâ ad angulum 115° flexâ, umbone centrali, costis tenuibus ab umbone utrinque radiantibus; carinæ tectis et superioris et inferioris partis rectis, planis, lævibus.

_Foss._--In Cretaceâ superiore Formatione.

7. _Scalpellum Hagenovianum_, Bosquet. (Idem, Tab. 4, fig. 13-16.)

S. carinæ umbone ad 1/6 totius ab apice longitudinis posito; carinæ tecto plano, utrinque sulcato; parietum et intra-parietum confluentium parte superiore solummodò cristis instructo ab umbone radiantibus.

_Foss._--In Cretaceâ superiore Formatione.

8. _Scalpellum radiatum_, Bosquet.[158] (Idem, Tab. 4, fig. 17-18.)

[158] Scalpelli 4 aliæ species fossiles, ad secundam generis
sectionem pertinentes, à Dom. Bosquet descriptæ et nominatæ
sunt. Jam cum equidem, ubi valvæ disjunctæ reperiuntur, nomina
specifica non nisi carinis (et interdùm scutis) tribuere soleam,
_S. pulchellum_, Bosq., hic inserere non possum, cujus scuti aut
carinæ fragmenta valdè imperfecta solùm reperta sunt. _Scalpellum
gracile_, _S. pygmæum_, et _S. radiatum_, Bosq., omnia _Scalpello
maximo_ et ejus varietatibus tam propè associantur, ut, cum ipse
specimina non viderim, characteres breves diagnosticos hic exhibere
non audeam. Veruntamen, cum Dom. Bosquet se hujus rei penitus
peritum se probaverit, longissimè abest ut in dubium vocare velim
quin hæ species reverà distinctæ existant.

S. scuti superficie cristis tectâ, inter se aliquantùm distantibus, ab umbone radiantibus; scuti umbone propè medium marginis occludentis posito; termino superiore truncato, lato, non acuminato.

_Foss._--In Cretaceâ superiore Formatione.

[_Sectio_ ††.]

9. _Scalpellum rutilum_, Darwin. ('Lepadidæ,' p. 253, Tab. 6, fig. 2.)

S. (Fœm. an Herm.) valvis 14 sub-rufis; sub-carinâ nullâ; carinæ tecto plano, utrinque cristâ rotundatâ instructo, margine basali truncato. Lateribus superioribus latitudine duplo longioribus.

_Hab._--(?)

10. _Scalpellum villosum_, Leach. (Darwin, 'Lepadidæ,' p. 274, Tab. 6, fig. 8.)

S. (Herm.) valvis 14; sub-rostro et sub-carinâ præsentibus; carinâ pæne rectâ; laterum paribus tribus, pari superiore triangulo.

_Hab._--In maribus orientalibus.

11. _Scalpellum quadratum_, Dixon. (Darwin, 'Lepad. Foss.' p. 22, Tab. 1, fig. 3.)

S. tecto parietibusque carinæ planis, lævibus, simplicibus, margine basali fere rotundato. Lateribus superioribus quinque-lateralibus, lævibus.

_Foss._--In "Eocenâ Formatione" Anglicâ.

12. _Scalpellum fossula_, Darwin. ('Lepad. Foss.' p. 24, Tab. 1, fig. 4.)

S. carinâ intra-parietibus instructâ; tecto utrinque costis magnis, tumidis, superne planatis, marginato; margine basali obtusè acuminato. Lateribus superioribus quinque-lateralibus, costis duabus modicis ab apice ad marginem basalem continuatis.

_Foss._--In Cretaceâ superiore Formatione.

13. _Scalpellum maximum_, J. Sowerby. (Darwin, 'Lepad. Foss.' p. 26, Tab. 2, fig. 1-10.)

S. carinâ intra-parietibus instructâ; tecto subangulari vel subcarinato; margine basali rectangulariter acuto; totâ valvâ plus minusve introrsùm arcuatâ, sed margine interno ferè-recto; tecto transversè plus minusve convexo; superficie pænè lævi, striis paucis obsoletis longitudinalibus elevatis; tectum, parietes, et intra-parietes inter se costis plus minusve prominentibus separantur.

_Var. typicum_, (Tab. 2, fig. 1, 4, 5, 8.)

S. carinâ introrsùm leviter arcuatâ, latitudine valvæ altitudinem superante; tecto transversè leniter arcuato; parietibus intra-parietibusque angustis, superficie pæne lævi.

_Var. cylindraceum_, (Tab. 2, fig. 2.)

S. parte superiore carinæ liberè prominente, parte interiore intra-parietibus rotundatis, inflexis, itâ repletâ, ut pæne cylindrica fiat; superficie externâ lævi, tecto parietibusque pæne confluentibus.

_Var. sulcatum_, (Tab. 2, fig. 3.)

S. carinâ introrsùm valde arcuatâ, sub-carinatâ; valvæ latitudine circà dimidium altitudinis æquante, tecto transversè præruptè arcuato; parietibus intra-parietibusque latiusculis. Apice solidè repleto, liberè paululùm prominente; superficie externâ striis paucis, rotundatis, ad alterum vel utrumque latus costarum duarum tectum et parietes separantium.

_Foss._--In Cretaceâ a superiore Formatione.

14. _Scapellum lineatum_, Darwin. ('Lepad. Foss.' p. 35, Tab. 2, fig. 11, 12.)

S. superficie totâ carinæ lineis tenuibus, rotundatis, longitudinalibus, proximis, microscopicis obtectâ; cristæ centralis costâ crassiore; costis duabus vel tribus tectum et parietes separantibus; latitudine valvæ circa dimidium altitudinis æquante; intra-parietibus latiusculis, nullâ costâ conspicuâ a parietibus separatis; apice solidè repleto, aliquantulum liberè prominente.

_Foss._--In Cretaceâ inferiore Formatione.

15. _Scapellum hastatum_, Darwin. ('Lepad. Foss.' p. 37, Tab. 2, fig. 13.)

S. carinâ intra-parietibus, intrà paululùm positis, instructâ; valvâ totâ introrsùm valdè arcuatâ, margine interno non recto; margine basali acuto, lanceolato; valvâ tenui, lævi, tecto transversè leniter arcuato; parietibus à tecto vix disjunctis.

_Foss._--In "Grey Chalk, Dover."

16. _Scalpellum angustum_, Dixon. (Darwin, 'Lepad. Foss.' p. 37, Tab. 1, fig. 2.)

S. carinâ angustâ, introrsùm valdè arcuatâ; tecto à parietibus rectangulè inflexis costâ, (ut videtur) disjuncto; intra-parietibus usque ad dimidium valvæ pertinentibus, deinde obliquè et abruptè truncatis; margine basali acutè cuspidato.

_Foss._--In Cretaceâ Formatione.

17. _Scalpellum quadricarinatum_, Reuss. (Darwin, 'Lepad. Foss.' p. 38.)

S. carinâ intra-parietibus latis (ut videtur) instructâ; tecto transversè plano, lævi, costâ prominente utrinque marginato; margine basali abruptè truncato.

_Foss._--In "Untern Pläner-Kalke, Bohemia."

18. _Scalpellum trilineatum_, Darwin. ('Lepad. Foss.' p. 38, Tab. 1, fig. 5.)

S. carinæ tecto transversè leniter arcuato, subcarinato, costâ centrali et costis duabus lateralibus, rotundatis, tumidis; parietibus angustis leviter concavis, rectangulè inflexis.

_Foss._--In "Grey Chalk, Dover."

19. _Scalpellum simplex_, Darwin. ('Lepad. Foss.' p. 39, Tab. 1, fig. 9.)

S. carinâ lævi; parietibus angustissimis, rectangulè inflexis; tecto subcarinato, transversè mediocriter arcuato; margine basali rectangulè acuminato.

_Foss._--In "Lower Greensand."

20. _Scapellum arcuatum_, Darwin. ('Lepad. Foss.' p. 40, Tab. 1, fig. 7.)

S. valvarum lineis angustis elevatis ab apice radiantibus: carinæ tecto transversè leniter arcuato, et parietibus rectangulè inflexis, leniter concavis, lævibus.

_Foss._--In "Gault."

21. _Scalpellum solidulum_, Steenstrup. (Darwin, 'Lepad. Foss.' p. 42, Tab. 1, fig. 8.)

S. valvarum lineis latiusculis elevatis ab apice radiantibus. Carinæ parte superiori liberè prominente, et cristâ centrali, internâ, longitudinali instructâ.

_Foss._--In Cretaceâ superiore Formatione; Scaniâ.

22. _Scalpellum tuberculatum_, Darwin. ('Lepad. Foss.' p. 43, Tab. 1, fig. 10.)

S. valvarum lineis tenuibus, tuberculatis, elevatis, ab apice radiantibus: carinæ tecto transversè leniter arcuato, et parietibus striatis: scuti umbone prope in medio marginis occludentis posito, costis duobus ab umbone ad angulum basi-lateralem, et ad basalis marginis medium decurrentibus.

_Foss._--In Cretaceâ Formatione.

23. _Scalpellum semiporcatum_, Darwin. ('Lepad. Foss.' p. 44, Tab. 1, fig. 6.)

S. carinâ ignotâ: scuti costis duobus ab umbone ad angulum basi-lateralem et ad marginis basalis medium decurrentibus; superficie inter hanc costam et marginem occludentem lineis tenuibus, longitudinalibus, elevatis instructâ.

_Foss._--In Cretaceâ superiore Formatione; Scaniâ.

24. _Scalpellum_ (?) _cretæ_, Steenstrup. (Darwin, 'Lepad. Foss.' p. 45, Tab. 1, fig. 11.)

S. valvis lævibus tenuissimis: scuti umbone propè medium marginis occludentis posito; costis tribus obscuris ab umbone ad angulos tergo-lateralem et basi-lateralem, et ad medium marginis basalis decurrentibus: carinæ apice et margine basali acutis; distincti parietes absunt.

_Foss._--In Cretaceâ Formatione.

11. _Genus_--POLLICIPES.

†. _Scuta, aut lævia aut lineis incrementi tenuibus solùm notata._

A. _Scuta, costâ ab apice ad centrum marginis basalis non decurrente._

B. _Scuta, costâ, nonnunquam subobsoletâ, ab apice ad centrum marginis basalis decurrente._

††. _Scuta, aut longitudinaliter aut transversè (i. e. secundum lineas incrementi) costata._

[_Sectio_ †, A.]

1. _Pollicipes cornucopia_, Leach. (Darwin, 'Lepadidæ,' p. 298, Tab. 7, fig. 1.)

P. capitulo, valvarum duobus aut pluribus sub rostro verticillis instructo: valvis albis, aut glaucis: pedunculo, squamarum densis verticillis symmetricè dispositis.

_Hab._--In Europâ.

2. _Pollicipes elegans_, Lesson. (Darwin, 'Lepadidæ,' p. 304.)

P. capitulo, valvarum duobus aut pluribus sub rostro verticillis instructo: valvis et pedunculi squamis rufo-aurantiacis: squamarum verticillis densis symmetricè dispositis.

_Hab._--In Peruviâ et Mexico.

3. _Pollicipes polymerus_, G. B. Sowerby. (Darwin, 'Lepadidæ,' p. 307, Tab. 7, fig. 2.)

P. capitulo, valvarum duobus, tribus, aut pluribus sub rostro verticillis instructo; valvis sub-fuscis; lateribus à supremo ad infimum gradatim quoad magnitudinem positis; carinæ margine basali (introrsùm spectanti) ad medium excavato; pedunculi squamarum verticillis densis, symmetricè dispositis.

_Hab._--In Californiâ et Oceano Pacifico meridionali.

4. _Pollicipes spinosus_, Quoy. (Darwin, 'Lepadidæ,' p. 324, Tab. 7, fig. 4.)

P. capitulo valvarum uno aut pluribus sub rostro verticillis instructo: laterum pari superiore vix inferioribus longiore: membranâ valvas tegente (post desiccationem) subfuscâ flavescente: pedunculi squamis inæqualibus, non symmetricis: verticillis longiusculè distantibus.

_Hab._--Novâ Zealandiâ.

5. _Pollicipes sertus_, Darwin. ('Lepadidæ,' p. 327, Tab. 7, fig. 5.)

P. capitulo valvarum uno aut pluribus sub rostro verticillis instructo: laterum pari superiore vix inferioribus longiore: membranâ valvas tegente (post desiccationem) fusco rufescente obscuro: rostro dimidiam carinæ longitudinem æquante, superficiei internæ altitudine latitudinem plus duplo superante: pedunculi squamis inæqualibus, non symmetricis: verticillis longiusculè distantibus.

_Hab._--Novâ Zealandiâ.

6. _Pollicipes concinnus_, J. Morris. (Darwin, 'Lepad. Foss.' p. 50, Tab. 3, fig. 1.)

P. scutis pæne quadratis, margine basali propè rostrum subconcavo, segmento tergo-laterali, è lineis incrementi, ut videtur, reflexis formato, lato, rotundato et prominente: tergis latis, pæne quadratis: carinæ margine basali, ut videtur, acuto.

_Foss._--In 'Oxford Clay.'

7. _Pollicipes ooliticus_, Buckman. (Darwin, 'Lepad. Foss.' p. 51, Tab. 3, fig. 2.)

P. scutis triangulis; superficie undulatâ; margine basali rectangulè ad marginem rectum tergo-lateralem posito; segmentum tergo-laterale è lineis reflexis incrementi formatum deest. Carinâ pæne rectâ, semi-cylindricâ, margine basali quadrato.

_Foss._--In 'Stonesfield Slate.'

8. _Pollicipes Nilssonii_, Steenstrup. (Darwin, 'Lepad.' Foss. p. 52, Tab. 3, fig. 11.)

P. scutis triangulis, planis: margine basali cum margine occludente angulum pæne rectum, cum margine recto tergo-laterali, angulum aliquanto minorem formante: deest segmentum tergo-laterale, è lineis incrementi reflexis formatum. Carinâ introrsùs admodùm arcuatâ, crassâ; marginis basalis mucrone obtuso.

_Foss._--In Cretaceâ superiore Formatione; Scaniâ.

9. _Pollicipes Hausmanni_, Koch. (Darwin, 'Lepad. Foss.' p. 53, Tab. 3, fig. 3.)

P. scutis subtriangulis, angulo basi-laterali valde rotundato; apice producto; margine basali cum margine occludente angulum pæne rectum formante; internâ apicis superficie prominente, margineque tergali sulcato.

_Foss._--In 'Hilsthon,' Germaniâ.

10. _Pollicipes politus_, Darwin. ('Lepad.' Foss. p. 54, Tab. 3, fig. 4.)

P. scutis ferè rhombicis, lævissimis; margine basali cum margine occludente angulum recto majorem formante; margine occludente projecturâ parietali, lineari, minutâ instructo; internâ apicis superficie concavâ.

_Foss._--In 'Gault.' (?)

11. _Pollicipes elongatus_, Steenstrup. (Darwin, 'Lepad. Foss.' p. 55, Tab. 3, fig. 5.)

P. scutis pæne quadratis; margine occludente et parte inferiori marginis tergo-lateralis rectangulè ad marginem basalem positis; apice obtuso.

_Foss._--In Cretaceâ Formatione albâ. Daniâ.

12. _Pollicipes acuminatus_, Darwin. ('Lepad. Foss.' p. 56, Tab. 3, fig. 6.)

P. scutis elongatis, triangulis; margine basali cum margine occludente angulum recto longè minorem formante; internâ apicis superficie concavâ.

_Foss._--In Cretaceâ Formatione.

13. _Pollicipes Angelini_, Darwin. ('Lepad. Foss.' p. 56, Tab. 3, fig. 7.)

P. scutis elongatis, triangulis, margine basali propè angulum rostralem in prominentiam obliquè rotundatam producto; internâ apicis superficie prominente, margine occludente sulcato.

_Foss._--In Cretaceâ superiore Formatione.

14. _Pollicipes reflexus_, J. Sowerby. (Darwin, 'Lepad. Foss.' p. 58, Tab. 3, fig. 8.)

P. scutis tenuibus, subovalibus; margine basali cum margine occludente angulum recto longè majorem formante; costâ obsoletâ rotundatâ ab apice ad angulum basi-lateralem decurrente, valvam in duas ferè æquales partes separante. Carinâ lineari, transversè abruptè arcuatâ; margine basali multum producto, apice truncato. Lateribus superioribus sub-pentagonis.

_Foss._--In Angliâ: 'Eocenâ Formatione.'

[_Sectio_ †, B.]

15. _Pollicipes carinatus_, Philippi. (Darwin, 'Lepad. Foss.' p. 60, Tab. 3, fig. 9.)

P. scutis crassiusculis ad formam trianguli æquianguli accedentibus; margine occludente externè costâ, humili firmato; costâ firmâ ab apice ad centrum marginis basalis decurrente; margine basali recto; angulo basi-laterali truncato, brevi; segmentum tergo-laterale ex lineis incrementi reflexis formatum, deest. Carinâ externè valdè carinatâ cum sulco laterali ad utrumque latus.

_Foss._--In Form. Tertiariâ, Siciliâ.

16. _Pollicipes glaber_, Roemer. (Darwin, 'Lepad. Foss.' p. 61, Tab. 3, fig. 10.)

P. scutis subtenuibus, latiusculis, ad formam trianguli æquianguli accedentibus; margine basali non prorsus recto; tergo-laterali segmento e zonis incrementi reflexis formato, ubi (latissimum), reliquæ valvæ dimidium æquante: margine tergali apicis intùs sulcato. Carinæ margine basali obtusè acuminato. Lateribus superioribus triangulis, tertiam partem longitudinis tergorum æquantibus. Lateribus anticis inferioribus singulis costâ propè terminum marginis basalis decurrente.

_Foss._--In Cretaceâ, super. et inferiore Formatione.

17. _Pollicipes unguis_, J. Sowerby. (Darwin, 'Lepad. Foss.' p. 64, Tab. 4, fig. 1.)

P. scutis incognitis, verisimiliter ut in P. glabro. Margine basali carinæ obtusè acuminato, sub-rotundato. Lateribus superioribus elongatis triangularibus, dimidium longitudinis tergorum superantibus. Lateribus anticis inferioribus costâ subcentrali instructis.

_Foss._--In 'Gault.'

18. _Pollicipes validus_, Steenstrup. (Darwin, 'Lepad. Foss.' p. 68, Tab. 4, figs. 2 and 3.)

P. scutis crassis, angustis; margine occludente externè costâ rotundatâ forti firmato; intus prominentiâ rostrali infra marginem rectum basalam dependente; costâ ab apice ad marginem basalem propiùs ad rostralem quam ad basi-lateralem angulum accedente. Carinâ lævissimâ, transversè semicylindricâ; parte superiori liberè prominente, internè aut planâ aut cristâ centrali instructâ.

_Foss._--In Cretaceâ sup. Formatione, Scaniâ et Maestricht.

19. _Pollicipes Darwinianus_, Bosquet. (Monographie Crust. Foss. de Limbourg, Tab. 1, fig. 8-16.)

P. scuti marginibus basali et occludente angulum solum 35° formantibus; intùs prominentiâ rostrali infra marginem basalem dependente; costâ ab apice ad marginem basalam propemodùm ad angulum rostralem accedente. Tergo pæne pentagono, intùs prominentiâ à medio marginis scutalis surgente.

_Foss._--In Cretaceâ superiore Formatione.

20. _Pollicipes dorsatus_, Steenstrup. (Darwin, 'Lepad. Foss.' p. 69, Tab. 4, fig. 4.)

P. scutis crassis; ad formam trianguli æquianguli accedentibus; margine occludente externè costâ rotundatâ firmato; angulo basi-laterali latè truncato, dimidium longitudinis marginis basalis veri, æquante; tergo-laterali segmento ex lineis incrementi reflexis formato, angustissimo. Tergorum costâ rectâ, latâ, proclivi, ab apice ad angulum basalem decurrente; angulo basali scutum versùs, obliquè truncato.

_Foss._--In Cretaceâ superiore Formatione, Daniâ.

[_Sectio_ ††.]

21. _Pollicipes mitella_, Linn. (Darwin, 'Lepadidæ,' p. 316, Tab. 7, fig. 3.)

P. capitulo valvarum unico sub rostro verticillo instructo: laterum pari superiore (introrsum spectanti) inferiorum magnitudinem ter aut quater superante: lateribus inferioribus utrinque obtegentibus: pedunculi squamarum verticillis densis, symmetricè dispositis.

_Hab._--In Insulis Indicis orientalibus.

22. _Pollicipes striatus_, Darwin. ('Lepad. Foss.' p. 70, Tab. 4, fig. 5.)

P. valvis longitudinaliter striatis: scutis sub-triangulis, margine tergo-laterali valdè arcuato et prominente; costâ obscurâ, rotundatâ, ab apice ad angulum basi-lateralem decurrente; internâ apicis superficie solidè repletâ, sine sulco manifesto.

_Foss._--In Cretaceâ superiore Formatione, Angliâ.

23. _Pollicipes semilatus_, Darwin. ('Lepad. Foss.' p. 72, Tab. 4, fig. 6.)

P. valvis longitudinaliter et transversè costatis: scutorum margine basali brevi, recto, cum margine occludente angulum rectum formante; costâ parietali tenuissimâ ab apice, ad angulum prominentem basi-lateralem decurrente; hæc valvam in duas partes inæquales dividit, è quibus portio tergo-lateralis latior est.

_Foss._--In Cretaceâ Formatione.

24. _Pollicipes rigidus_, J. Sowerby. (Darwin, 'Lepad. Foss.' p. 73, Tab. 4, fig. 7.)

P. valvis transversè costatis: scutorum margine basali recto, cum margine occludente angulum recto majorem formante; costâ angustissimâ, parietali, ab apice ad angulum basi-lateralem decurrente: tergis, costâ curvâ, parietali, ad angulum basalem decurrente instructis; apice basali in prominentiam parvam terminante, lateribus prominentiæ parallelis.

_Foss._--In 'Gault.'

25. _Pollicipes fallax_, Darwin. ('Lepad. Foss.' p. 75, Tab. 4, fig. 8.)

P. valvis transversè costatis: scutis margine basali non recto, angulum pæne rectum cum margine occludente formante; costâ, parietibus obliquis, ab apice ad angulum basi-lateralem decurrente: tergis, costâ curvatâ, parietibus obliquis, ad angulum basalem latum, rotundatum, decurrente.

_Foss._--In Cretaceâ superiore Formatione, Angliâ, Scaniâ, Hanoveriâ.

26. _Pollicipes elegans_, Darwin. ('Lepad. Foss.' p. 76, Tab. 4, fig. 9.)

P. valvis longitudinaliter et transversè striatis: scutorum margine basali recto, cum margine occludente angulum recto paulo majorem formante; costâ parietali, latiore quam pro solitâ incrementorum linearum latitudine, ab apice ad angulum basi-lateralem decurrente: tergorum costâ parietali, rectâ, ad apicem basalem, acuminatum decurrente.

_Foss._--In Cretaceâ superiore Formatione, Scaniâ, Daniâ.

[_Species aliquot quas, scutis incognitis, auctores a valvis insignibus nominârunt, hìc pro tempore solummodo iterum describuntur._]

27. _Pollicipes Bronnii_, F. Roemer. (Darwin, 'Lepad. Foss.' p. 77, Tab. 4, fig. 10.)

P. carinâ lævi, subcarinatâ, margine basali arcuato et turgido; totâ valvâ vel extrorsùm arcuatâ vel pæne rectâ; internè, costis duabus elevatis ad utrumque latus partis superioris liberè prominentis.

_Foss._--In 'Upper Greensand,' et 'Hils-conglomerat.'

28. _Pollicipes planulatus_, J. Morris. (Darwin, 'Lepad. Foss.' p. 27, Tab. 4, fig. 11.)

P. tergis subrhombicis, latis, lævibus, apice basali latè truncato, latitudine dimidium longitudinis marginis occludentis æquante; apice basali truncato angulum rectum cum margine scutali formante; parte superiori marginis scutalis cuspidem latam, rotundatam, leviter prominentem formante.

_Foss._--In 'Oxford Clay.'

12. _Genus_--LITHOTRYA.

1. _Lithotrya dorsalis_, G. B. Sowerby. (Darwin, 'Lepadidæ,' p. 351, Tab. 8, fig. 1 _a′_.)

L. scutis terga angustè obtegentibus: carinâ intùs concavâ; rostro, duorum aut trium squamarum subjacentium latitudinem æquante: lateribus, squamarum quinque subjacentium longitudinem æquantibus, superficie internâ angustè ellipticâ: pedunculi squamis superioribus verticillum secundum minus duplo superantibus.

_Hab._--Insulis Indicis occidentalibus.

2. _Lithotrya cauta_, Darwin. ('Lepadidæ,' p. 356, Tab. 8, fig. 3.)

L. scutis terga amplè obtegentibus: carinâ intus concavâ: rostro, squamarum subjacentium latitudinem vix æquante: lateribus, squamas subjacentes sesquitertio superantibus, superficie internâ latè ellipticâ: pedunculi squamis superioribus verticillum secundum pæne quadruplo superantibus.

_Hab._--In Australiâ.

3. _Lithotrya Nicobarica_, Reinhardt. (Darwin, 'Lepadidæ,' p. 359, Tab. 8, fig. 2.)

L. scutis terga angustè obtegentibus: carinæ cristâ internâ tenui in parte superiore positâ: rostro conspicuo, squamarum sex subjacentium latitudinem æquante: lateribus, superficie internâ triangulâ squamarum septem subjacentium latitudinem æquantibus.

_Hab._--In Insulis Nicobaricis et Timor.

4. _Lithotrya rhodiopus_, J. E. Gray. (Darwin, 'Lepadidæ,' p. 363, Tab. 8, fig. 4.)

L. scutis terga amplè obtegentibus: carinæ cristâ internâ tenui, in parte superiore positâ: lateribus, superficie internâ symmetricè et latè ovatâ, carinæ latitudinis plus quam tertiam partem æquantibus: tergorum basali apice tenui, et angulo carinali producto: rostro et pedunculo ignotis.

_Hab._--(?)

5. _Lithotrya truncata_, Quoy. (Darwin, 'Lepadidæ,' p. 366, Tab. 9, fig. 1.)

L. scutis in profundam tergorum plicam insertis: carinæ cristâ centrali prominente et rotundatâ in parte superiore: rostro et lateribus rudimentalibus, carinæ latitudinis quindecimam fere partem æquantibus.

_Hab._--In Arch. Philippino et Mari Pacifico.

6. _Lithotrya Valentiana_, J. E. Gray. (Darwin 'Lepadidæ,' p. 371, Tab. 8. fig. 5.)

L. scutis in profundam tergorum plicam insertis: tergorum opposito superiore margine, plicâ alterâ æquè profundâ instructo: carinæ cristâ prominente centrali, marginibus quadratis, in parte superiore: rostro rudimentali: lateribus et pedunculo ignotis.

_Hab._--In Mari Rubro.

13. _Genus_--LORICULA.

1. _Loricula pulchella_, G. B. Sowerby, jun. (Darwin, 'Lepad. Foss.' p. 81, Tab. 5.)

_Foss._--In Cretaceâ inferiore Formatione.

ORDO II. ABDOMINALIA.

1. _Genus_--CRYPTOPHIALUS.

1. _Cryptophialus minutus_, Darwin. ('Balanidæ,' p. 566, Tab. 23 et 24.)

_Hab._--In littore occidentali Americæ meridionalis.

ORDO III. APODA.

1. _Genus_--PROTEOLEPAS.

1. _Proteolepas bivincta_, Darwin. ('Balanidæ,' p. 589, Tab. 24 et 25.)

_Hab._--In insulis Indicis occidentalibus.

DESCRIPTION OF PLATES.

PLATE 1.

BALANUS TINTINNABULUM.

Fig.
_a_, _b_, and
_f_ (upper shell), Balanus tintinnabulum,--_var._ communis.
_c_ and _f_ (part of shell), " " " validus.
_d_, " " " " coccopoma.
_e_, " " " " concinnus.
_f_ (part of shell), " " " validus.
_g_, " " " " zebra.
_h_, " " " " crispatus.
_i_, " " " " spinosus.
_k_, " " " " occator.
_l_, " " " " d'Orbignii.

PLATE 2.

_Genus_--BALANUS.

Fig.
1 _a_, Balanus tintinnabulum,--_var._ communis, scutum.
1 _b_, " " " occator "
1 _c_, 1 _d_, and 1 _e_, " " " communis "
1 _f_, " " " coccopoma "
1 _g_, " " " concinnus "
1 _h_, (magnified) " " (_young_) " vesiculosus "
1 _i_, and 1 _k_, " " " communis, tergum.
1 _l_, " " " coccopoma "
1 _m_,and 1 _n_, " " " d'Orbignii "
1 _o_, " " " coccopoma "
2 _a_, 2 _b_, 2 _c_, 2 _d_, Balanus tulipiformis, scutum and
tergum, external and internal views of.
3 _a_, 3 _b_, 3 _c_, 3 _d_, Balanus psittacus, scutum and tergum,
external and internal views of.
4 _a_, 4 _b_, Balanus Capensis, scutum and tergum, internal view of.
5 _a_, 5 _b_, Balanus nigrescens " "
6 _a_, Balanus decorus, scutum, internal view; 6 _b_, tergum,
external view.
7 _a_, Balanus vinaceus, scutum, internal view; 7 _b_, do.
external view; 7 _c_, tergum, external view; 7 _d_, basal
edge of the parietes of one of the compartments, showing the
cancellated structure of the inner lamina.

PLATE 3.

_Genus_--BALANUS.

Fig. 1 _a_, Balanus Ajax; 1 _b_, scutum external; 1 _c_, tergum
external; and 1 _d_, scutum, internal view.
2 _a_, 2 _b_, Balanus stultus, scutum and tergum, external
views; 2 _c_ and 2 _d_, scutum, internal and external views.
3 _a_, Balanus calceolus; 3 _b_, variety; 3 _c_, scutum,
internal view; 3 _d_, tergum, internal view; 3 _e_, spur of
tergum toothed.
4 _a_, Balanus galeatus; 4 _b_, 4 _c_, scutum and tergum,
internal view.
5 _a_, 5 _b_, Balanus cymbiformis, scutum and tergum,
internal view.
6 _a_, Balanus navicula; 6 _b_, 6 _c_, scutum and tergum,
internal view; 6 _d_, scutum, external view.
7 _a_, Balanus trigonus; 7 _b_ and 7 _c_, scutum, external
views, two varieties; 7 _d_, scutum, internal view; 7 _e_
and 7 _f_, tergum, external views, two varieties.

PLATE 4.

_Genus_--BALANUS.

Fig. 1 _a_ and 1 _b_, Balanus spongicola, external views of
scutum and tergum; 1 _c_, _var._ of the tergum, from a
specimen from the Cape of Good Hope; 1 _d_, _var._ of the
tergum from the West Indies.
2, Balanus lævis.
2 _a_, " " fossil, elongated _var._, showing
lower part of basal cup filled
up with a cancellated mass.
2 _b_ and 2 _c_, " " scutum, external and internal view
of.
2 _d_ and 2 _e_, " " scutum (_variety_), internal and
external view of.
2 _f_, " " scutum (_variety_), external view.
2 _g_, " " tergum, external view.
3 _a_, Balanus perforatus, scutum, internal view; 3 _b_,
tergum, internal view; 3 _c_, tergum, _var._ external view.
4 _a_, Balanus concavus (_var._ from Panama), scutum,
internal view; 4 _b_, scutum, external view; 4 _c_, tergum,
external view; 4 _d_, tergum, fossil, Coralline Crag; 4
_e_, tergum, fossil, Italy.

PLATE 5.

_Genus_--BALANUS.

Fig. 1 _a_, Balanus perforatus,--_var._ angustus.
1 _b_, " " " Cranchii.
1 _c_, " " " mirabilis.
1 _d_, " " " fistulosus.
2 _a_, " amphitrite,--_var._ venustus.
2 _b_, " " _var._ cirratus.
2 _c_, " " " pallidus.
2 _d_, " " " Stutchburii.
2 _e_, " " " communis.
2 _f_, " " " niveus.
2 _g_, " " " obscurus.
2 _h_, " " scutum, _var._ communis.
2 _i_, " " " " Stutchburii.
2 _k_, " " tergum, " pallidus.
2 _l_, " " " " communis.
2 _m_, 2 _n_, and 2 _o_," " _var._ Stutchburii.
3 _a_, Balanus pœcilus, scutum, internal view; 3 _b_, tergum,
external.
4 _a_, Balanus eburneus, scutum, external view; 4 _b_,
tergum, external; 4 _c_, scutum, internal; 4 _d_, tergum
(_var._), internal.

PLATE 6.

_Genus_--BALANUS.

Fig. 1 _a_, Balanus improvisus; 1 _b_, scutum, internal; 1 _c_,
tergum, external view.
2 _a_, Balanus nubilus, scutum, internal view; 2 _b_, tergum,
ditto; 2 _c_, tergum, external view.
3 _a_, 3 _b_, Balanus corrugatus, scutum and tergum, internal
view.
4 _a_, Balanus porcatus; 4 _b_ and 4 _c_, scutum and tergum,
internal views; 4 _d_, tergum external; 4 _e_, basal edge
of the parietes of wall of shell.
5 _a_, Balanus patellaris; 5 _b_, scutum, internal; 5 _c_,
tergum, external.
6 _a_, Balanus crenatus.
6 _b_, " " smooth _var._
6 _c_, " " elongated _var._
6 _d_ and 6 _e_, " scutum and tergum, external views.
6 _f_ and 6 _g_, " " " internal views.

PLATE 7.

_Genus_--BALANUS.

Fig. 1 _a_, Balanus glandula, scutum, internal; 1 _b_, tergum,
external.
2 _a_, Balanus balanoides; 2 _b_, portion of basal edge of
parietes of a compartment; 2 _c_, tergum; 2 _d_, tergum,
_var._
3 _a_, Balanus cariosus; 3 _b_, portion of basal edge of
parietes of a compartment; 3 _c_, scutum, internal view of;
3 _d_, tergum, internal; 3 _e_, tergum, external view.
4 _a_, Balanus declivis, lateral view, with basal membrane
removed; 4 _b_, rostrum (to left hand), two lateral
compartments, and carina; 4 _c_ and 4 _d_, scutum and
tergum, external views.
5 _a_, Balanus Hameri; 5 _b_, scutum, internal view; 5 _c_,
tergum, external view.
6 _a_, Balanus amaryllis; 6 _b_, scutum, internal; 6 _c_,
tergum, external view.
7 _a_, Balanus allium; 7 _b_ and 7 _c_, scutum, external and
internal views; 7 _d_, tergum, external.
8 _a_, Balanus cepa, scutum, internal; 8 _b_, scutum,
external; 8 _c_, tergum, external view.

PLATE 8.

_Genus_--BALANUS.

Fig. 1, Balanus quadrivittatus.
2 _a_, Balanus terebratus, part of basis seen from the
outside; 2 _b_, the same, seen from within.
3 _a_, Balanus vestitus, scutum, internal view; 3 _b_,
tergum, external view.
4 _a_, Balanus imperator, scutum, internal view; 4 _b_,
tergum, external view; 4 _c_, portion of basal edge of wall
of the shell.
5 _a_, Balanus flosculus.
5 _b_, " " _var._ sordidus.
5 _c_, " " scutum, internal view.
5 _d_, " " " " _var._
5 _e_ and 5 _f_, " tergum, internal and external views of.
6 _a_, Balanus bisulcatus, scutum, external view; 6 _b_,
tergum, external view; 6 _c_, scutum, internal view.
7, Balanus dolosus, tergum, external view.
8 _a_, Balanus unguiformis, scutum, internal view; 8 _b_,
tergum, do.
9, Balanus varians, tergum, external view.
10 _a_, Balanus inclusus.
10 _b_, " " _var._ that has been attached to a
branch of a coralline.
10 _c_, " " " seen from beneath, showing the
narrow furrowed basis and wide
lateral compartments; the other
four compartments, namely, the
two carino-lateral, the carina,
and rostrum, being of very small
size.

PLATE 9.

_Sub-Genus_--ACASTA.

Fig. 1 _a_, Acasta spongites; 1 _b_, scutum, external view; 1
_c_, scutum, internal; 1 _d_, tergum, internal.
2 _a_, Acasta sulcata; 2 _b_, _var._, lateral compartment of;
2 _c_ and 2 _d_, terga, internal views of two varieties.
3 _a_, Acasta cyathus; 3 _b_ and 3 _c_, scutum and tergum,
internal views.
4, Acasta undulata, scutum, external view.
5 _a_, Acasta glans, basis seen from within; 5 _b_,
compartments of a smaller specimen, seen from within;
carina on the right-hand, cut into two; carino-lateral
and lateral compartments to the left-hand; 5 _c_, tergum,
internal view.
6 _a_, Acasta lævigata, tergum, internal view; 6 _b_, another
_var._
7 _a_, Acasta fenestrata; 7 _b_, scutum, and 7 _c_, tergum,
internal views.
8 _a_, Acasta purpurata; 8 _b_, scutum; 8 _c_, tergum,
internal views.
9 _a_, Acasta sporillus; 9 _b_, carino-lateral compartment
(almost rudimentary) and lateral compartment, seen from
within; 9 _c_ and 9 _d_, scutum and tergum, seen from
within.

PLATE 10.

_Genus_--TETRACLITA.

Fig. 1 _a_, Tetraclita porosa, _var._ communis.
1 _b_, " " " rubescens.
1 _c_, " " " nigrescens.
1 _d_, " " " elegans.
1 _e_, " " " communis, young, with radii
developed.
1 _f_, " " " patellaris.
1 _g_, " " basal edge of wall of shell.
1 _h_, " " basal edge of wall of shell, _var._
elegans, showing also the
structure of one of the
rudimentary radii or sutures.
1 _i_, " " internal view of scutum; 1 _k_, do.
of tergum; 1 _l_, do. of scutum,
_var._; 1 _m_, do. of tergum, _var._
2 _a_, Tetraclita serrata; 2 _b_, portion of external surface
of wall, low down, near basis; 2 _c_ and 2 _d_, scutum and
tergum, internal views.
3 _a_, Tetraclita rosea, scutum; 3 _b_, tergum; 3 _c_, whole
shell; 3 _d_, basal edge of wall of shell.

PLATE 11.

_Genera_--TETRACLITA AND ELMINIUS.

Fig. 1 _a_, Tetraclita purpurascens, _var._ with surface
disintegrated, and with the sutures united and obliterated.
1 _b_, Tetraclita purpurascens, _var._ well preserved, with
the radii developed; 1 _c_ and 1 _d_, _var._ scutum and
tergum, internal views.
2 _a_, Tetraclita costata; 2 _b_ and 2 _c_, scutum and tergum.
3 _a_, Tetraclita vitiata; 3 _b_, basal edge of portion of
wall; 3 _c_ and 3 _d_, scutum and tergum, internal views
of; 3 _e_, tergum, internal view, _var._
4 _a_, Tetraclita cœrulescens; 4 _b_, scutum and tergum
united, external view; 4 _c_ and 4 _d_, scutum and tergum,
internal views.
5 _a_, Tetraclita radiata; 5 _b_, scutum and tergum united,
external view; 5 _c_ and 5 _d_, scutum and tergum, internal
views.
6 _a_, Elminius Kingii; 6 _b_ and 6 _c_, scutum and tergum,
internal views of; 6 _d_, tergum, _var._ external view of;
6 _e_, tergum, another _var._ internal view of.

PLATE 12.

_Genera_--ELMINIUS AND PYRGOMA.

Fig. 1 _a_, Elminius modestus; 1 _b_, scutum, internal view;
1 _c_, tergum, internal view; 1 _d_, do., tergum, _var._;
1 _e_, do., tergum, _var._
2 _a_, Elminius plicatus; 2 _b_, basal edge of portion of
wall of shell; 2 _c_ and 2 _d_, scutum and tergum, internal
views of; 2 _e_ and 2 _f_, scutum and tergum, internal
views of, _var._
3, Elminius simplex; shell.
4 _a_, Pyrgoma Anglicum; 4 _b_ and 4 _c_, scutum and tergum,
internal views.
5 _a_, Pyrgoma cancellatum, shell, seen from above; 5 _b_,
shell seen on the under side; 5 _c_ and 5 _d_, scutum and
tergum, external views; 5 _e_ and 5 _f_, scutum and tergum,
internal views of.
6, Pyrgoma Stokesii, shell imbedded in coral.
7 _a_, Pyrgoma conjugatum, shell, external view of; 7 _b_,
scutum and tergum, calcified together, seen from the
outside; 7 _c_, do., internal view of.

PLATE 13.

_Genera_--PYRGOMA AND CREUSIA.

Fig. 1 _a_, Pyrgoma grande; 1 _b_, scutum and tergum, calcified
together, external view of; 1 _c_, scutum and tergum,
internal view of; 1 _d_, the two scuta and terga, external
view, seen from above, having their natural position, when
closed.
2 _a_, Pyrgoma milleporæ, shell viewed from above; 2 _b_,
internal view of, showing the sheath; 2 _c_, scutum and
tergum, united, external view of; 2 _d_, scutum, _var._
external view of; 2 _e_, scutum, internal view of; 2 _f_,
tergum, internal view of.
3 _a_, Pyrgoma dentatum shell, external view of; 3 _b_,
scutum, _var._ 1, external view of; 3 _c_, tergum, _var._
1, external view of; 3 _d_, tergum, _var._ 2, external
view of; 3 _e_, scutum, _var._ 3, external view of; 3 _f_,
tergum, _var._ 3, external view of; 3 _g_, scutum and
tergum, _var._ 1, joined together, internal view of.
4 _a_, Pyrgoma crenatum, scutum, external view of, showing
the great depending adductor plate and large occludent
ledge; 4 _b_, external view of.
5 _a_, Pyrgoma monticulariæ, external view of; 5 _b_, another
specimen, internal view of; 5 _c_, another specimen,
external view of; 5 _d_, portion of circumference of shell,
viewed externally, much magnified, showing the outer
lamina, and the irregular, longitudinal septa; 5 _e_,
another specimen of the same, with the longitudinal septa
more regular; 5 _f_, scutum and tergum completely calcified
together, external view of.
6 _a_, Creusia spinulosa, shell, seen from above.
6 _b_, 6 _c_, Creusia spinulosa, _var._ 1, scutum and tergum,
internal view of; 6 _d_, scutum and tergum, joined
together, external view of.
6 _e_, 6 _f_, 6 _g_, Creusia spinulosa, _var._ 2, 6 _e_,
scutum, internal view; 6 _f_, tergum, internal view of;
6 _g_, tergum, of another specimen, internal view of.
6 _h_, Creusia spinulosa, _var._ 3, scutum and tergum joined
together, external view of.

PLATE 14.

_Genera_--CREUSIA AND CHELONOBIA.

Fig. 6 _i_, 6 _k_, 6 _l_, Creusia spinulosa, _var._ 4, 6 _i_,
tergum, external view; 6 _k_, the same, from another
individual; 6 _l_, the same, internal view.
6 _m_, Creusia spinulosa, _var._ 5, tergum, external view.
6 _n_, 6_o_, 6_p_, 6_q_, Creusia spinulosa, _var._ 6, 6 _n_,
scutum, external view of; 6 _o_, tergum of same individual,
external view of; 6 _p_, scutum of another individual,
external view of; 6 _q_, tergum of latter, external view of.
6 _r_, Creusia spinulosa, _var._ 7, scutum, internal view of.
6 _s_, Creusia spinulosa, _var._ 9, scutum and tergum,
calcified together, external view.
6 _t_, Creusia spinulosa, _var._ 10, scutum and tergum,
calcified together, external view.
6 _U_, Creusia spinulosa, _var._ 11, shell seen from above; 6
_u_, scutum and tergum, calcified together, external view.

Fig. 1 _a_, Chelonobia testudinaria, shell seen from above; a
specimen has been chosen, with some of the radii smooth,
and others more or less notched; 1 _b_, scutum, internal
view of; 1 _c_, tergum, internal view of; 1 _d_, scutum and
tergum, joined together, external view of.
2, Chelonobia caretta, shell seen from above.
3 _a_, Chelonobia patula, shell seen from above; 3 _b_,
tergum, external view of.
4, Carina of Chelonobia patula, seen from within; _a a_, outer
lamina of wall, joined by the longitudinal septa to _b_,
the inner lamina; _e c e_, sheath, descending to the base
of shell, with the middle part largely hollowed out; the
upper part of the sheath, above _d d_, is transversely
marked by the lines of attachment of the opercular
membrane; _d_, _d_, alæ.
5, View of the edge of the radius of the rostrum of Chelonobia
testudinaria.
_a_, _a_, inner portion of radius.
_b_, thick outer lamina of the radius, transversely pitted;
beneath this pitted portion, which forms only the outer
surface of the radius, and distinct from the inner portion
_a_, the arborescent and dentated sutural edges of this
outer lamina are seen.
_c_, outer lamina of wall of compartment.
_d_, the exterior septum, connecting the outer lamina of
the wall to the inner lamina; the basal edge of the inner
lamina of the wall is seen beneath and without the lower
end of the inner portion (_a_) of the radius.

PLATE 15.

_Genera_--CHELONOBIA AND CORONULA.

Fig. 1, Transverse section of shell of Chelonobia testudinaria.
B A B, Compound rostrum: A being the true rostrum.
B B, the rostro-lateral compartments, which normally, in
the Balaninæ, are quite confounded with the true rostrum:
the sutures separating these three compartments are not
continued through the outer lamina.
C, left-hand lateral compartment.
D, left-hand carino-lateral compartment.
E, carina.
S S, Sutures, six in number, separating the six compartments.
_a_, outer lamina of wall of compartment, whence the
radiating, longitudinal septa (left unshaded) arise, and at
the opposite end blend into the indistinct inner lamina,
viz. _b_, (see fig. 4, in last plate.)
_c′_, sheath.
_d_, ala, forming, as usual, part of the sheath.
_e_, inner portion of the radius.
_f_, _f_, outer lamina of the radius (see _b_, in fig. 5,
in last plate), of great thickness, and externally deeply
pitted;--the sharp ridges between the pits, produce in the
section the points, such as that marked by the outer _f_.
2, Coronula balænaris, shell seen from above.
2 _a_, " " section of one of the transverse
circumferential loops, formed by the
folded wall of a compartment. The wall
itself is formed of an outer and inner
lamina, with longitudinal septa. The
internal surfaces of the loop-part are
connected by special shelly plates or
longitudinal septa.
2 _b_, " " scutum and tergum united together by the
opercular membrane (with horny ridges),
seen from the inner side.
3, Coronula diadema, shell, seen from the outside; 3 _a_,
scutum and tergum joined together by the opercular
membrane, seen from the outside; 3 _b_, scutum cleaned and
enlarged, seen from the inside.
4, Section, in a vertical plane, through the skin of a whale,
on which a _Coronula diadema_ had been attached, but has
been wholly removed: the two curved, horn-like projections
occupied two of the eighteen cavities on the under side of
the shell, formed by the folded walls: the blacker part is
the epidermis; the lighter part is the yellowish fibrous
tissue of the skin under the epidermis.
5, Coronula reginæ, shell seen from the outside.
6, Coronula barbara, internal view of the basal margin and
inside of one of the compartments, exhibiting the
circumferential transversely looped ends of the folds of
the wall, with the inner surface transversely wrinkled.
7-9, diagrams, showing how one of the circumferential transverse
loops of the wall becomes divided into two transverse
loops, thus giving rise to another fold in the wall.
10, diagrams, showing how the wall of the young shell in
Coronula, from being (_a_) simply sinuous, becomes deeply
folded (_b_); the folds lastly (_c_) expanding transversely
at their ends, thus giving rise to the circumferential
transverse loops, as in fig. 7.

PLATE 16.

_Genus_--CORONULA.

Fig. 1, rostrum, viewed from the inner side, of _Coronula
diadema_.
_a_, sheath, marked transversely in the upper part by the
attachment of the opercular membrane.
_b_, furrow on each side of (_a_), receiving the edges of the
thick alæ of the adjoining lateral compartments.
_c′′_, special plate, on which the alæ on their outer sides
rest.
_d_, radius, on the edge it may be just seen to consist of an
outer layer (the normal radius), and a much thicker inner
part (the pseudo or complementary radius) formed of oblique
denticulated septa.
_e e′ e′′_, basal edge of wall, which from its commencement
at _e_, or _e′′_ can be followed, folding up to near the
basal edge of the sheath, to its termination at _e′′_ or
_e_.
_f_, serrated lines of junction between the folds of the wall.
2, Lateral compartment of _C. diadema_, seen laterally, on a
smaller scale than last fig., but taken from the same
shell; letters of reference the same: this figure, if the
ala _a′_ were removed, would do for a lateral view of the
rostrum, or fig. 1.
_a_, sheath, much foreshortened.
_a′_, ala (therefore also part of sheath), and the edge of
which fits into _b_ of fig. 1.
_b_, furrow receiving edge of ala of the adjoining
carino-lateral compartment.
_c′′_, special plate, seen edgeways.
_d_, radius, the division into two parts, viz., the thin
outer normal radius, and the under pseudo or complementary
radius here shown (rather exaggerated) plainer than in fig.
1.
_e_, basal edge of wall; to the right hand the three folds at
their inner ends are seen obliquely, one behind the other:
these are seen directly in front in fig. 1.
3, lateral compartment of _C. balænaris_, seen laterally;
letters of reference the same as in last fig., but _c′′_
not introduced for this plate is barely developed, and
only in the lower part, and is attached to the radius: _g
g_ points where fresh folds have been formed in the walls
along the lines of suture, as may be seen in the outline of
the wall in fig. 5.
4, lateral compartment of _C. reginæ_, seen laterally; letters
of reference the same as in the last two figures.
5, Coronula balænaris, outline of the basal margin of the
folded walls: _s_, _s_, the six sutures. The wall can be
continuously followed from one end of a suture to the next
suture.
6, Coronula diadema; small portion of the external surface of
the wall, close to the basal edge, highly magnified; _a_,
outer lamina, not extending down to the basal edge; _b_,
inner lamina; _c_, projecting longitudinal septa.
7, Coronula diadema; transverse section through the upper part
of the shell, showing the rostrum and the two adjoining
lateral compartments (and the alæ of the carino-lateral
compartments), all supposed to be a little separated from
each other, so that the sutures, _s s_, are shown by white
lines.
A A A, rostrum.
C C, lateral compartments.
D D, carino-lateral compartments, of which only the alæ
(_a′_) are shown.
Of the letters in italics, those which occur in figs. 1, 2, 3,
4, 5, refer all to the same parts, viz.:--
_a_, sheath, continuous with (_a′_) the alæ, where such occur.
_c′′_, special plate on which the alæ rest.
_d_, radius, divided into a thin outer normal radius, and the
inner complementary portion, the latter shaded by convex
lines of growth.
_d′_ is a special tube (seen only as a black dot) for a
thread of corium.
_e_, folded walls.
_f_, junction of the folded walls (see _f_, in fig. 1)
leading into the cavities (_f′_) open beneath, and filled
up by the epidermis (see Pl. 15, fig. 4) of the whale.
_h_, inside of the transverse loops of wall, occupied by
corium: in the enlarged section of a loop, in C. balænaris,
in Pl. 15, fig. 2 _a_, the opposed sides are seen to be
connected by shelly longitudinal plates.
_v_, cavity occupied by the ovarian tubes and cæca.

PLATE 17.

_Genera_--PLATYLEPAS, TUBICINELLA, AND XENOBALANUS.

Fig. 1 _a_, Platylepas bissexlobata, shell of, viewed from the
under side; A, rostrum; B, lateral compartment; C,
carino-lateral compartment; E, carina. These letters are
placed opposite the inward folds of each compartment
forming the midribs.
1 _b_, Platylepas bissexlobata, shell of, viewed externally.
1 _c_, " " scutum and tergum, viewed
externally and separated.
1 _d_, " " lateral compartment, viewed
from the inside, showing the
inward folded wall or midrib;
_a′_, ala; _d_, radius.
2 _a_, Platylepas decorata, shell, viewed externally; A,
rostrum; B, lateral compartment; C,
carino-lateral compartment; E,
carina. These letters are placed
opposite the inward folds of each
compartment.
2 _b_, " " minute portion of external
surface of wall, magnified.
3 _a_, Tubicinella trachealis, natural size; _p_, tubular
soft lip leading into sack; _s_, scutum; _t_, tergum.
3 _b_, Tubicinella trachealis, carino-lateral compartment of
a young specimen, natural size; _e_, broken summit of wall;
_d_, radius: the dotted lines, connecting the two figures,
show the size and form which this compartment would have
attained, if it could have grown without the summit
constantly breaking away.
3 _c_, Tubicinella trachealis, scutum and tergum viewed from
within, and connected by layers of thickened membrane; the
scutum is to the left-hand.
4 _a_, Xenobalanus globicipitis, enlarged; _b_, skin of the
porpoise, with the shell imbedded; at _c_ the lower end of
the prosoma of the included animal's body is supposed to be
seen through.
4 _b_, Xenobalanus globicipitis, shell greatly enlarged, seen
from above, with the basal membrane at the bottom; the
peduncle-formed body having been removed.
A, rostrum, on the inner side of this and the adjoining
compartments, the transversely ribbed sheath can be seen.
B, lateral compartment.
C, carino-lateral compartment.
E, carina; these compartments are separated by the sutures
_s s_, which run from the top of the shell to the bottom,
along the ends of the six rays formed by the adjoining
portions of the inwardly folded compartments.
_a_, alæ, of rectangular shape.
_d_, pseudo, or complimentary radii.
4 _c_, Xenobalanus globicipitis, small portion of external
surface of wall of shell, showing the external lamina,
_a a_, which consists only of narrow ledges (expanding
and contracting) on each side of the longitudinal septa,
_c_; _b_, the internal lamina.

PLATE 18.

_Genus_--CHTHAMALUS.

Fig. 1 _a_, Chthamalus stellatus, shell, _var. a_ (communis).
1 _b_, " " " " _e_ (depressus).
1 _c_, " " " " _c_ (communis).
1 _d_, " " " " _d_ (fragilis).
1 _e_, " " scutum and tergum, viewed inside,
_var. c_, British.
1 _f_, " " scutum and tergum, viewed inside,
_var. a_, Madeira.
1 _g_, " " scutum and tergum, viewed inside,
_var. e_, Mediterranean.
1 _h_, " " scutum and tergum, viewed inside,
_var. c_ and _e_, St. Jago,
Cape de Verde Arch.
2, Chthamalus antennatus, shell.
3 _a_, Chthamalus dentatus, shell; 3 _b_, _var._ shell,
attached to a ship's bottom; 3 _c_, tergum, viewed from
within.
4 _a_, Chthamalus cirratus, scutum, viewed on inside; 4 _b_,
tergum, viewed on inside.
5 _a_, Chthamalus Hembeli, shell, old specimen.
5 _b_, Chthamalus Hembeli, younger shell; C, carino-lateral
compartment; _a′_, ala; _d_, radius; E, carina; _a′_, the
two alæ.
5 _c_, Chthamalus Hembeli, scutum, external view of; 5 _d_,
tergum, external view of; _e_, two of the crests, to which
the tergal depressor muscles are attached, much enlarged
and viewed from vertically beneath, showing the lateral
denticuli or sub-crests.
6 _a_, Chthamalus fissus, shell; 6 _b_, scutum and tergum,
separated, internal views of.

PLATE 19.

_Genera_--CHTHAMALUS, CHAMÆSIPHO, AND PACHYLASMA.

Fig. 1 _a_, Chthamalus intertextus, shell; 1 _b_, scutum and
tergum, calcified together, with the suture obliterated in
the upper part, internal view of.
2 _a_, Chthamalus scabrosus, shell; 2 _b_, scutum, internal
view of; 2 _c_, tergum, internal view, _p_, plate forming
one side of the cavity in which the depressor muscle is
attached; 2 _d_, tergum, as seen from almost vertically
beneath; _p_, pit for the depressor muscle; _q_, special
pit for the lateral, properly scutal depressor muscle; _r_,
articular furrow.
3 _a_, Chamæsipho columna, shell; A, rostrum; B, lateral
compartment, probably formed by fusion of the
rostro-lateral and lateral compartments; _E_, carina;
3 _b_, 3 _c_ scutum and tergum, internal views of.
4 _a_, Chamæsipho scutelliformis, shell much enlarged, seen
from above; A, rostrum, separated by imperfect sutures from
the (B) lateral compartments, which are formed probably by
the fusion of the rostro-lateral and lateral compartments;
E, carina; B stands opposite one of the inward folds of
the wall, leading into one of the tubular apertures, which
runs (generally with an irregular spiral curve) through
the whole thickness of the shell down to the surface of
attachment. The carina has two of these apertures.
4 _b_, Chamæsipho scutelliformis, another specimen, seen from
the under side, letters of reference the same.
4 _c_, Chamæsipho scutelliformis, rostrum, disarticulated,
enlarged, showing the alæ.
4 _d_, Chamæsipho scutelliformis, scutum and tergum, internal
views of.
5 _a_, Pachylasma giganteum; 5 _b_, rostrum of an extremely
young specimen, much enlarged, showing its compounded
nature, viz., of a true rostrum and rostro-lateral
compartments; 5 _c_, scutum and tergum, external views of;
5 _d_, scutum and tergum, internal views of.

PLATE 20.

_Genera_--PACHYLASMA, OCTOMERIS, AND CATOPHRAGMUS.

Fig. 1 _a_, Pachylasma aurantiacum, shell, lateral view; A,
rostrum, separated only by the finest suture from B,
the rostro-lateral compartment, which latter has a mere
rim-like radius on the side facing the lateral (C)
compartment. The latter (C) has a great ala, and is
separated from the (D) carino-lateral compartment, by the
finest suture; D has a rim-like radius; E, carina, with
very large alæ (_a_).
1 _b_, Pachylasma aurantiacum, inside view of about half the
shell, showing the compound rostrum, consisting of the true
rostrum (A) and the two rostro-lateral (B, B) compartments;
of the latter, that to the left has a shoulder, receiving
the ala of the lateral compartment which has been removed;
the ala of the lateral compartment extends, in the
upper part, over the whole width of the rostro-lateral
compartment, as may be seen on the right-hand, B; C,
lateral compartment; D, carino-lateral compartment, with a
shoulder (_b_) to receive the ala of the carina, which has
been removed.
1 _c_, 1 _d_, Pachylasma aurantiacum, scutum and tergum,
external views of.
2 _a_, Octomeris angulosa, shell seen from above; 2 _b_,
scutum and tergum, internal views of.
3 _a_, Octomeris brunnea, shell seen from above; 3 _b_,
scutum and tergum, external views of.
4 _a_, Catophragmus polymerus, shell seen from above.
4 _b_, " " external view of one of the
scales or valves, from the second
whorl, counting from the inside.
4 _c_, " " outline of the basal edges of all
the valves of a shell; A,
rostrum; B, rostro-lateral; C,
lateral; D, carino-lateral
compartments; E, carina.
4 _d_, " " external view of a portion of the
shell of a much corroded and worn
down specimen, serving almost as
a transverse section; C, lateral
compartment, D, carino-lateral
compartment.
4 _e_, " " scutum and tergum, internal views
of.

PLATE 21.

_Genus_--VERRUCA.

N.B.--_Letters of reference the same throughout the Plate._