Chapter X: Part 10

COLOUR.—(_In spirits._) Yellowish grey, becoming paler beneath. Three
or four dark transverse streaks across the head from eye to eye:
beneath the eye one or two indistinct streaks, passing off towards
the branchial orifice: also two very distinct longer ones commencing
on the upper part of the snout before the eyes, and passing
obliquely across the cheeks towards the roots of the pectorals,
parallel to those last mentioned. Besides the above, there are
several obliquely transverse interrupted lines on the sides of the
body: in one specimen, these lines are not well-defined; in another,
they are distinct, but so much interrupted as to have the appearance
of spots arranged in a linear series. Two or three transverse lines
encircling the tail; and some remains of longitudinal stripes on the
second dorsal and anal fins.

The above description is that of two very small specimens of a species of _Balistes_ taken by Mr. Darwin in Lat. 14° 20′ South, Long. 38° 8′ West, about sixty-five miles from land. I have very little doubt of their being the young of the _B. Vetula_ of Bloch. The only respects in which they appear to differ from that species are the oblique lines on the back being carried completely across the sides in the form of lines of spots, and the anterior portions of the second dorsal and anal fins not being prolonged in a point; but both these differences may be the effect of immaturity.

2. BALISTES ACULEATUS. _Bl._

Balistes aculeatus, _Bloch_, Ichth. tab. 149.
———— _Benn._ in Zool. of Beechey’s Voy. p. 69. pl. 22. f. 2.

FORM.—Body deep, subrhombic. Tail armed with three rows of prickles,
eleven in the uppermost row, about nine or ten in the middle one,
and five or six in the lowermost. A few larger scales than the
others behind the branchial orifice. Pelvic bone very rough and
prickly, the spines that follow short, and not protruding much
beyond the skin. First spine in the dorsal very strong, aculeated at
the anterior edge, but not at the sides; no third spine in this fin.
Second dorsal and anal even. Caudal rounded.

D. 2—24; A. 21; C. 12; P. 13.
Length 2 inc. 3 lin.

COLOUR.—Not noticed in the recent state. The ground colour has
probably been altered by the spirit, but the markings are still very
distinct, and accord tolerably with Bloch’s figure, except that the
oblique bands on the posterior part of the body, in front of and
above the anal, are darker; while they alternate with four white
ones, which are particularly conspicuous. Possibly these white bands
may have been originally blue, as the narrow stripes descending from
the eyes to the pectorals, which evidently were of that colour, are
nearly faded to a white. There is also a white stain on each side of
the tail, where the spines are, which appears to have been blue
originally: the spines themselves are deep shining black.

This specimen shows the black transverse bands between the eyes, and
the broad band passing from the eye to the pectoral, between the
narrow blue ones above alluded to, all represented by Bloch, but not
observed by Mr. Bennett in the specimen figured in the “Zoology of
Beechey’s Voyage.”

Habitat, Tahiti.

The above specimen was taken by Mr. Darwin at Tahiti. It is quite small, and differs in some respects from the figures of Bloch and other authors, but it is evidently referable to the _B. aculeatus_. The species is probably subject to variation in respect of colouring.

1. ALEUTERES MACULOSUS. _Richards._

Aleuteres maculosus, _Richards._ in Proceed. of Zool. Soc. 1840. p. 28.

FORM.—Oval, somewhat approaching to fusiform behind, very much
compressed. The greatest depth one-third of the entire length. Skin
covered with little granular points, terminating in very minute
bristles, and communicating a slight roughness to the touch, when
the finger is passed from tail to head. Snout rather prominent and
acute: jaws equal. Dorsal spine springing from above the middle of
the orbit of the eye; strong, with four rows of sharp prickles at
the four angles, pointing downwards, and very regularly set: second
dorsal spine very minute. The second dorsal and anal fins have been
lost in this specimen, and their form and number of rays cannot be
determined. The pectorals are small, each with twelve rays. Caudal
rounded, also with twelve rays.

Length 5 inc. 4 lines.

COLOUR.—“Mottled with pale blackish-green, leaving white spots.”—D.—In
its present state, the skin is nearly gone from long maceration in
impure spirit: such portions as are left accord well with Dr.
Richardson’s description, appearing of a mouse-grey, with darker
mottlings. There are three or four rather indistinct dark asciæ
across the caudal.

Habitat, King George’s Sound.

I have scarcely any doubt of this being the _A. maculosus_ described by Dr. Richardson, in his recently published notes on a collection of fishes from Van Diemen’s Land. Mr. Darwin’s specimen, which is in bad condition, was obtained by him in King George’s Sound.

2. ALEUTERES VELUTINUS. _Jen._

_A. pallide fuscescens, fasciis quatuor obscurioribus,
longitudinalibus, indistinctis; pinnis pallide aurantiis: corpore
oblongo-ovali elongato; cute delicate hispidâ, scabrâ: rostro
producto, apice obtuso: spinâ dorsali aculeis lateralibus deflexis,
uniseriatis: pinnis dorsali secundâ et anali multum ante caudalem
desinentibus._

D. 2—33; A. 31; C. 12; P. 13 vol 14.
LONG. unc. 8.

FORM.—Elongated, approaching to oblong-oval, the tail rather slender.
Greatest depth exactly one-fourth of the entire length, and
equalling the length of the head, this last being measured to the
upper angle of the oblique branchial orifice. Back slightly arched,
the curvature rather exceeding that of the belly. Profile in front
of the dorsal spine falling very gradually, and not much out of the
rectilineal. Snout considerably produced, but blunt at the
extremity. Mouth small; jaws equal; teeth strong, and very sharp.
Eyes round, placed exactly above the branchial orifice. The grains
on the skin are coarser than in the _A. maculosus_, and the bristles
springing from them longer and more developed, especially on the
posterior part of the body, communicating a harsher feel to the
touch: these bristles are slightly hooked at their extremities, the
tips being turned towards the tail.

Dorsal spine strong, situate above the posterior part of the orbit,
with only two principal rows of prickles, one on each of the two
lateral edges; anteriorly granulated at bottom, with a few
rudimentary prickles towards the apex, but posteriorly almost quite
smooth. Second spine very minute. The distance from the first spine
to the commencement of the second dorsal fin equals twice the length
of that spine. The anal commences under the fifth dorsal ray, and
ends nearly in a line with the termination of that fin, but extends
a trifle further. Both fins fall short of the caudal by a
considerable space. Pectorals rather small. The caudal is worn at
the end, but appears to have been either square or slightly rounded.

COLOUR.—“Very pale brown: fins pale orange.”—D.

A _second specimen_ is smaller than the above, measuring six inches
and three quarters in length. It is exactly similar in respect to
form, and general colour; but the sides are marked with four
tolerably distinct longitudinal bands, extending from the branchial
orifice to the caudal, rather darker than the ground on which they
are traced. There is very little indication of these bands in the
first specimen.

Habitat, King George’s Sound.

This species was taken by Mr. Darwin in King George’s Sound, and appears to be new. It has some points of resemblance with the _Balistes Ayraud_ of Quoy and Gaimard, but in that the dorsal fin is said to extend to the caudal,[49] which is far from being the case here. I have named it _velutinus_, in respect of the minute bristles which cover the skin, somewhat resembling the pile of velvet.

OSTRACION PUNCTATUS. _Schn._

L’Ostracion pointillé, _Lacép._ Hist. Nat. des Poiss. tom. i. p. 455. pl. 21. fig. 1. Ostracion punctatus, _Schneid._ Syst. Ichth. p. 501. ———— Meleagris, _Shaw_, Nat. Misc. pl. 253.

This well-marked species of Ostracion, first described by Lacépède from Commerson’s MSS., and afterwards figured by Shaw, in his “Naturalist’s Miscellany,” under the name of _O. Meleagris_, was obtained by Mr. Darwin at Tahiti, where it had been previously observed by Captain Cook.

There are two specimens in the collection, both exactly similar, and of the same size, measuring a trifle more than three inches and a half in length. They also accord well with Shaw’s figure. Lacépède, in his description, speaks of the anal fin as being more extended than the dorsal, and as having eleven rays; but in both Mr. Darwin’s specimens, I find the number of rays in these two fins the same. The formula is as follows:

D. 9; A. 9; C. 8; P. 10.

Schneider has noticed this species twice; first under the name of _lentiginosus_, and again under that of _punctatus_.

CYCLOSTOMI.

FAMILY.—PETROMYZONIDÆ.

MYXINE AUSTRALIS. _Jen._

FORM.—Scarcely differing from the _M. glutinosa_, but apparently
rather more slender in proportion to its length. Mouth and cirriform
appendages the same. Branchial orifices two, very near together,
placed beneath, at a little beyond one-fourth of the entire length.
A very conspicuous row of pores along each side of the abdomen. The
tail seems somewhat sharper than in the _M. glutinosa_, and the rays
of the low fin which turns round its extremity rather more distinct.
Vent distant from the end of the tail rather less than one-eighth of
the entire length.

Length 11 inc. 6 lin.

COLOUR.—“Above coloured like an earth-worm, but more leaden; beneath
yellowish; head purplish.”—D.

Habitat, Tierra del Fuego.

Mr. Darwin obtained this species by hook amongst the kelp, in Goree Sound, and other parts of Tierra del Fuego, where he observes it is abundant amongst the rocky islets. Its extreme southern locality would suggest the idea of its being distinct from the _M. glutinosa_ of the northern seas; yet the differences between the two, upon comparison, are very slight, and, if it really be so, as I have ventured to consider it, it requires an examination of more specimens to lay down its exact specific character.

Mr. Darwin has made some interesting remarks on the habits of this fish. He observes that it is “very vivacious, and retained its life for a long time; that it had great powers of twisting itself, and could swim tail first. When irritated, it struck at any object with its teeth; and by protruding them, in its manner, much resembled an adder striking with its fangs. It vomited up a _Sipunculus_ when caught.” He adds, that he “observed a milky fluid transuding through the row of lateral pores.”

APPENDIX.

The following Appendix contains descriptions of a few species, which were omitted to be noticed in their proper places; and further remarks with respect to some, which will be found in the body of the work.

FAMILY.—PERCIDÆ.

1. APHRITIS UNDULATUS. _Jen._

PLATE XXIX. fig. 1.

_A. elongatus: lateribus supra pallide olivaceis, fasciis transversis
abbreviatis, lineisque longitudinaliter undantibus, nigris;
lateribus infra argenteis: pinnis dorsalibus et caudali punctatis;
pinnis, reliquis, et lineâ laterali, albidis._

B. 6; D. 8—25; A. 1/22; C. 14, et 6 brevioribus; P. 22; V. 1/5.
LONG. unc. 3. lin. 1.

FORM.—Elongated; the depth about one-sixth of the entire length; the
thickness two-thirds of the depth. depth. Head four and a half times
in the length. Profile falling very gradually at first, but more
rapidly in advance of the eyes, causing the snout to appear rather
obtuse. Mouth small: maxillary slender, hardly reaching to a
vertical line from the anterior margin of the orbit: upper jaw
slightly longer than the lower, and very protractile. Teeth very
minute, forming a narrow velutine band: a patch on the chevron of
the vomer scarcely visible, but capable of being very distinctly
felt; none apparent on the palatines. Eye one-fourth the length of
the head, and distant one diameter from the end of the snout; the
interocular space rather less than the diameter. Snout slightly
indented, or furrowed out in front of the eyes. A series of
impressions on the lower jaw, and along the limb of the preopercle,
but much less obvious than in the next species, and not distinctly
porous. Preopercle with the ascending margin vertical, the angle at
bottom rounded; the limb broad and distinctly marked, with the
boundary line between it and the cheek slightly elevated into a
ridge. The opercle, with its membrane, produced backwards in an
angle, the subopercle being visible beneath. The branchial membrane
six-rayed, and fastened to the isthmus underneath, the aperture
commencing beneath the ascending margin of the preopercle.

_Fish Pl. 29 Appendix._

_Waterhouse Hawkins del._
]

_1. Aphritis undulatus._ _Nat. Size._
_2. Iluocœtes fimbriatus._ „
_2a. „ Magnified View of Teeth._ „
_3. Phucocœtes latitans._ „
_3a. „ „ Teeth._ „

Lateral line commencing at the upper angle of the gill-opening, and
following the curvature of the back at one-fourth of the depth, and
preserving this direction throughout its course, not falling to the
middle before losing itself in the caudal. Scales small, covering
the whole head and body, except the snout in front of the eyes, the
jaws, and the limb of the preopercle. The free portion of each scale
marked with several small concentric circles, the free edge finely
ciliated: the basal portion with a fan of seven striæ, and the
spaces between these deeper striæ with minuter striæ running
transversely: the basal margin cut square.

Pectorals attached rather low down, and a little posterior to the
terminating angle of the opercle; their length about three-fourths
that of the head: the fourth to the eighth rays longest; the first
ray only half the length of the second; the first two, and the last
three or four, simple; the rest branched. Ventrals about four-fifths
the length of the pectorals, and in advance of those fins by nearly
half their own length; their spine very distinct. First dorsal
short, commencing immediately above the insertion of the pectoral:
all the spines very slender, with the intervening membrane delicate;
the second longest, equalling about half the depth; the third and
following ones gradually decreasing. Second dorsal long, separated
from the first by a very small interval, and occupying a space just
equal to the distance between its commencement and the end of the
snout: the rays gradually decreasing in length from the anterior
ones, which equal three-fourths of the depth; all simple, or if
branched, only so at their extreme tips. The interval between the
second dorsal and the caudal contained eight and a half times in the
entire length. Anal commencing under the sixth ray of the second
dorsal, or exactly at the middle point of the entire length, caudal
excluded; extending a trifle beyond the second dorsal, but in other
respects answering to that fin. Caudal square when spread, but very
slightly notched when the rays are close; contained six and a half
times in the entire length; the principal rays branched.

COLOUR.—(_In spirits._) Back and upper half of the sides pale
olivaceous, with about seven or eight abbreviated, transverse, dusky
fasciæ; beneath these are two irregular lines undulating
longitudinally in a zig-zag manner, and having rather a tendency to
meet at the angles, so as to form a connected longitudinal chain of
diamond-shaped links. Lower portion of the sides and abdomen
silvery. Tubal pores of the lateral line white, making this line
very evident. Dorsal and caudal fins speckled with small dusky spots
and points. Pectorals, ventrals, and anal, quite plain, and whitish.

A _second specimen_ in the collection exactly resembles the above,
except in being not quite so large, and in having a ray less in each
of the two dorsal fins.

Habitat, Chonos Archipelago, W. coast of S. America.

The genus _Aphritis_ was first established by M. Valenciennes, in the appendix to the eighth volume of the “Histoire des Poissons,” for the reception of a small Percoid fish obtained by MM. Quoy and Gaimard in Van Dieman’s Land, inhabiting fresh-water. The species above described, which was taken by Mr. Darwin in Lowe’s Harbour, South of Chiloe, appears to be referable to the same genus. It differs, however, in many respects from the _A. Urvillii_, the only one which Valenciennes has noticed. The relative situation of the first dorsal with respect to the pectorals, and of the anal with respect to the second dorsal, is different: there are fewer rays in the anal, and more in the second dorsal: the upper, instead of the lower jaw, as represented in Valenciennes’s figure, is rather the longest; neither can I discern any teeth on the palatines, though there is a patch of very minute ones in front of the vomer.

That this species really belongs to _Aphritis_, would seem indicated not merely by the aggregate of its external characters, but by the internal structure also, which was examined in one of the two specimens brought home by Mr. Darwin, and found conformable to what is stated by Valenciennes, in this respect, of the _A. Urvillii_. The stomach is large, with four very distinct cœcal appendages, and there is no air-bladder.

The _A. undulatus_, which I have so named in reference to the undulating longitudinal lines on the sides, is very Cypriniform in general appearance, and not altogether unlike the common minnow, _Cyprinus Phoxinus_.

2. APHRITIS POROSUS. _Jen._

_A. brevior: pallide olivaceus, lateribus fasciis transversis
obsoletis nigricantibus; pinnis omnibus brunneis: maxillâ inferiore,
et limbo preoperculi, poris conspicuis circiter novem,
suborbitalibus circiter quinque, seriatim dispositis._

D. 8—25; A. 1/22; C. 14, &c.; P. 23; V. 1/5.
LONG. unc. 2. lin. 5.

FORM.—Not so much elongated as the last species: the depth rather more
than one-sixth of the entire length, and the head only four times in
the same. Also distinguished by a row of large mucous pores on the
lower jaw, passing upwards posteriorly, and continued along the limb
of the preopercle: the number of these pores on each side is nine or
ten: a row of similar pores, amounting to about five, passes
backwards from a little above the end of the maxillary beneath each
eye. In other respects, the form is similar to that of the last
species, excepting that the interval between the second dorsal and
the caudal is only one-eighth of the entire length, in consequence
of the body being less elongated.

COLOUR.—(_In spirits._) Back and upper half of the sides, olivaceous
brown; beneath silvery. No very obvious markings; but traces may be
seen of six or seven transverse dusky fasciæ, reaching from the back
to a little beneath the lateral line, which were probably more
distinct in the recent state. All the fins brownish; the dorsal a
little powdered with dusky specks. The fourth and fifth rays of the
ventrals are white, and appear to have been always of a different
colour from the rest of the fin.

Habitat, Coast of Patagonia.

This appears to be another new species of _Aphritis_, taken by Mr. Darwin on mud-banks, in Port Desire, central Patagonia. It is very closely allied to the _A. undulatus_, but, I conceive, certainly distinct. There is but one specimen in the collection.

FAMILY.—SCORPÆNIDÆ.

APISTUS ——?

Mr. Darwin’s collection contains a species of this genus procured in King George’s Sound, New Holland, which, from the bad state of preservation of the specimen, it is scarcely possible to identify with certainty. Possibly it may be new, as it does not seem to accord very exactly with any of those described in the “Histoire des Poissons;” but I shall not consider it such, nor do more than point out a few of its more obvious characters.

It is not determinable, whether it was originally one of the naked
species of this genus, or whether the scales have been rubbed off, but
probably the former. The suborbital and preopercular spines are
strong, and considerably developed: the former reaches back further
than the maxillary, and nearly to the posterior part of the orbit, and
has another very small spine at its base. The lower jaw advances
beyond the upper. The head is about one-third of the entire length.
The eyes are large, their diameter being contained about three and a
half times in the length of the head. The dorsal commences in a line
with the ascending margin of the preopercle. The first spine is half
the length of the second; the second is a little shorter than the
third, which is longest, and equals two-thirds of the depth of the
body; the fourth and succeeding ones decrease very gradually; the soft
portion of this fin is a little higher than the hinder part of the
spinous. The first anal spine is rather more than half the length of
the second, which is the strongest of the three, though not much
longer than the third. The pectorals are rather pointed, and a little
shorter than the head. The ventrals are attached a little behind the
pectorals, and are not very much shorter than those fins.

The following is the fin-ray formula:

D. 13/9; A. 3/6; C. 11, &c.; P. 11; V. 1/5.
Length 4 inches 6 lines.

The species to which this approaches nearest would seem to be the _A. niger_ of Cuvier and Valenciennes; but there is no appearance of the small elevations on the skin resembling hairs, which those authors mention in their description of this last, and, on the whole, I am inclined to consider it as distinct.

AGRIOPUS HISPIDUS. p. 38.

Notwithstanding what I have advanced in regard to this species, further consideration has inclined me to suspect, that it may prove ultimately only the young of the _A. Peruvianus_. In that case, however, it would appear that the absence of vomerine teeth can only be assigned as a character of this genus in the adult state.

FAMILY.—SCIÆNIDÆ.

OTOLITHUS ANALIS. _Jen._

This new species of _Otolithus_ is from Callao: it was omitted to be noticed in the body of the work. There is but one specimen in the collection, in bad condition, and not admitting of a very detailed description: but it is evidently distinct from all the species described by Cuvier and Valenciennes.

It is rather more elongated than the _O. Guatucupa_, the depth being
not much more than one-fifth of the entire length. The head is long,
and contained three and a half times in the same. The lower jaw is
considerably the longest. The teeth above are small, and
sharp-pointed, apparently in two rows, the outer row being a little
stronger than the inner: there are two very strong canines in front,
springing from between the rows. Below, the teeth are in two rows in
front, and one at the sides; those in front small, but those at the
sides unequally sized, three or four, standing at intervals, being
much stronger than the others, and very sharp. Diameter of the eye
about one-sixth the length of the head; its distance from the end of
the snout one diameter and a half.

The lateral line is continued to the extremity of the caudal, between
the ninth and tenth rays. There is a small interval between the two
dorsal fins. The second dorsal, as well as the anal, are longer than
in the _O. Guatucupa_, with more soft rays, especially the anal. The
pectorals are narrow and pointed, and between one-half and two-thirds
the length of the head. The ventrals are attached almost exactly
beneath the pectorals. The caudal appears to have been square.

D. 9—1/24; A. 1/16; P. 17; V. 1/5.
Length 12 inches.

COLOUR.—The colours were not noticed when recent, and can hardly be
judged of now. The general tint appears to have been silvery. If
there were any markings, no traces of them remain.

Habitat, Callao, Peru.

This species has a longer anal than any of the American species described by Cuvier and Valenciennes. I have in consequence named it _analis_.

PRIONODES FASCIATUS. p. 47.

It has been suggested that this may be nothing more than a monstrosity. Whether this be really the fact or not, can only be determined by the examination of more specimens. But in either case, I am so satisfied now of its being a _Serranus_ in all its essential characters, that I conceive it never can be placed in a different family from that genus. If the fact be established of its never possessing vomerine and palatine teeth, such a character can, at the very utmost, serve only to distinguish it as a subgenus in that group. But every day is bringing more and more to light the small value of that character.

STEGASTES IMBRICATUS. p. 63.

I am informed by Mr. Lowe, of Madeira, that this is the same as the
_Glyphisodon luridus_ of Cuvier and Valenciennes.[50] Their
description is so short, that I failed to recognize it; and I was
induced to consider it as a new genus from the circumstance of its
possessing vomerine teeth. Whether these teeth exist in any other
species, or have only been presumed absent in all, because not found
in some, I am not aware. But here again we see how little such a
character is to be depended upon.

FAMILY.—BLENNIDÆ.

Mr. Darwin’s collection contains two new forms from South America, closely allied to each other, yet forming distinct genera, and which will not enter into any of those described by authors. At first it was conceived that they were Malacopterygian fishes, more especially from their having all the rays in the dorsal and anal fins articulated; and to belong to the Apodal division of that group, from their being supposed to be without ventrals; but, on a closer inspection, the ventrals, which are very small, were found to have been overlooked, and it was evident altogether that the true place of these fishes in the system was amongst the _Blennidæ_. The mention of this circumstance will explain why they were omitted to be noticed in their proper place.

These two genera, so far as can be judged from the situations in which Mr. Darwin obtained them, have the same habits as the Blennies, lurking under stones and weeds; and I propose to give them respectively the names of _Iluocœtes_ and _Phucocœtes_.

GENUS.—ILUOCŒTES.[51] _Jen._

_Corpus elongatum, antice subcylindricum, postice compressum,
ensiforme, læve, nudum, alepidotum. Rostrum breve, obtusum,
rotundatum, ultrà maxillam inferiorem productum. Dentes acuti,
subconici, in utrâque maxillâ uniseriati: supra canini duo fortes,
curvati, antici, et præ serie exstantes: in vomere dentes pauci
acuti aggregati; in utroque palatino uniseriati. Lingua lævis. Oculi
grandes, prominuli. Apertura branchialis mediocriter fissa, membranâ
quinque-radiatâ. Maxillæ, os suborbitale, et præoperculum, tubiporis
cutaneis brevibus ad margines fimbriatæ. Pinnæ ventrales jugulares,
minutæ, gracilissimæ, triradiatæ. Pinnæ dorsalis et analis prælongæ,
caudali coalescentes, radiis omnibus articulatis._

If I am right in placing this new genus amongst the _Blennidæ_, it will evidently take its place next to _Zoarces_, to which it is more nearly allied than to any other group in that family. It agrees especially with _Zoarces_, not only in general form, but in having all the dorsal and anal rays articulated, (excepting one in the dorsal, which possibly may be an accident in the only specimen examined,) and in having the ventral fins extremely small. On the other hand, it departs from that genus, in having the body entirely naked, and free from scales; in the two remarkable canines in front of the upper jaw, and in having teeth on the palate; also in having no notch at the posterior part of the dorsal. It is further remarkable for its large prominent eyes, and the rows of tubipores on the cheeks. Amongst the true Malacopterygians, it approaches nearest to _Ophidium_, and, but for the circumstance of its possessing ventrals, it might perhaps be ranged under that genus. It is, however, evidently a connecting link between the _Apodal Malacopterygians_ and the _Blennidæ_.

Like the Blennies, this genus has neither cæcal appendages nor air-bladder. The intestinal canal is rather ample, with a few coils, but of tolerably equal dimensions throughout.

There is but one species of this new genus in the collection, which is from the Archipelago of Chiloe. The detailed description of it is as follows:—

ILUOCŒTES FIMBRIATUS. _Jen._

PLATE XXIX. Fig. 2.

FORM.—Very much elongated, subcylindric anteriorly, compressed and
ensiform behind. Greatest depth in the region of the pectorals, and
about one-tenth of the entire length. Head, measured to the extreme
point of the gill-cover, five and a half times in the same. The head
is rather larger than any part of the body, its depth and thickness
being equal, and each a trifle less than the depth of the body.
Crown and forehead a little flattened, whence the profile descends
in a curve before the eyes. Snout blunt and rounded, projecting,
both in front and at the sides, beyond the lower jaw. Gape wide, and
reaching to beneath the middle of the eye. Intermaxillary somewhat
protractile at the sides, but not in front; shorter than the
maxillary, with a considerable intervention of membrane between the
extremities of the two bones, which are not united posteriorly,
excepting by the membrane just mentioned. Maxillary long, rather
slender, of nearly uniform breadth and thickness throughout,
retiring in part beneath the suborbital, and reaching backwards to a
vertical from the posterior part of the orbit. Intermaxillary with a
single row of small, pointed, subconical, slightly curved teeth; in
front of these, and quite at the anterior extremity of the jaw, two
strong, hooked, regular canines:[52] the teeth in the row rather
wide asunder, and set a little irregularly, about thirty in number.
In the lower jaw, teeth few in number, scarcely more than eight or
ten in front, rather stronger than the intermaxillary series,
followed by a moderate canine on each side, these last smaller than
the ones above: at the sides of the lower jaw, beyond the canines,
scarcely more than one or two small teeth (possibly others are
fallen). A small cluster of three or four teeth on the fore part of
the vomer, like those in front of the lower jaw, and a row on each
palatine. Pharynx also armed with strong teeth; but the tongue,
which is free at the tip, and rounded, smooth. Eyes large and
prominent, and elevated rather above the line of the profile: their
diameter one-fourth the length of the head; their distance from the
end of the snout one diameter; the interocular space reduced to a
narrow channel, and scarcely equalling half a diameter.

Opercle of a triangular form; subopercle lanceolate, projecting
further than the opercle, and passing upwards and backwards to form
the terminating angle of the gill-cover. Gill-opening of very
moderate extent; the branchial membrane fastened down underneath,
with five rays. Skin smooth and naked, loose, and probably very
mucous in the living fish. Apparently no lateral line. The edges of
both jaws curiously fringed each with a row of tubipores, or
cutaneous appendages in the form of tubes, having pores at their
terminal extremities for the exudation of mucus. The row on the
upper jaw is continued along the margin of the suborbital on to the
cheek; that on the lower is carried upwards to form an edging to the
preopercle. There is also one of these tubipores at each nostril,
another behind each eye, and a third on each side of the nape.

The dorsal commences above the terminating angle of the gill-cover,
and extends the whole length of the body: its height nearly uniform
throughout, equalling half the depth: the rays slender; all
articulated, except the third, which is spinous, and shorter than
those which precede and follow it; mostly simple, but some of the
posterior ones slightly divided at their tips. Vent situate beneath
the termination of the first quarter of the dorsal. The anal begins
immediately behind it, and, like the dorsal, is carried on to the
end of the body, to unite with it in forming a pointed caudal; all
the rays soft and delicate. Pectorals rather pointed, with the
middle rays longest, and about two-thirds the length of the head.
Ventrals very minute and narrow, of only three rays, and appearing
like one filament, about one-third the length of the pectorals;
attached in front of the pectorals, and nearly in a line with the
gill-opening.

B. 5; D. about 80; A. about 60; C. about 15; P. 16; V. 3.
Length 5 inc. 9 lin.

COLOUR.—Not noticed in the recent state. In spirits it is nearly
colourless, with the exception of a dark bluish line along the base
of the dorsal; upper part of the head, and nape, also stained with
the same dark tint.

Habitat, Archipelago of Chiloe.

This species was taken by Mr. Darwin under stones. There is but one specimen in the collection, and it would be very desirable to see others, in order to ascertain whether the circumstance of the _third_ dorsal ray _alone_ being spinous, (those that precede as well as follow being articulated), is merely accidental in the one above described, or really characteristic of the species. If the latter, it is an anomaly,—a single spine thus occurring in the middle of a soft fin,—of which I know no other example.

GENUS.—PHUCOCŒTES.[53] _Jen._

_Corpus elongatum, compressum, nudum, alepidotum, porosissimum.
Rostrum breve, obtusum. Dentes acuti, subconici, in maxillâ
superiore uniseriati, in inferiore bi-vel tri-seriati; supra canini
duo fortiores, antici, et præ serie exstantes: in vomere dentes duo
vel tres acuti, quorum unus fortis; in utroque palatino uniseriati.
Lingua lævis. Oculi parvi. Apertura branchialis arctissima, membranâ
sex-radiatâ. Maxillarum margines poris conspicuis longitudinaliter
dispositis, simplicibus, haud in tubos productis. Pinnæ ventrales,
dorsalis et analis, ut in genere præcedenti._

This genus differs from _Iluocœtes_, in having the head and eyes smaller, the snout scarcely at all produced, the teeth in front of the lower jaw in two or three rows, and especially in the contracted gill-opening, which is reduced to a small hole, relatively not much larger than in the Eels, and in the branchial membrane having six rays. It wants also the tubal cutaneous appendages on the jaws and cheeks, in the place of which are rows of simple pores. It may be added that the whole skin is every where studded with pores; smaller, however, than those which form the maxillary series. The fins are similar, including the minute ventrals; but the tail and caudal are more rounded, and the membrane investing the rays of the dorsal and anal is more fleshy, so as hardly to allow of the rays being counted.

This genus is yet more eel-like, and more malacopterygian in general appearance than the last, serving to make the passage from the _Blennidæ_ to the apodal division of the soft-finned fishes, still more gradual and evident. Mr. Darwin obtained it at the Falkland Islands. There is but one species in the collection referable to it.

PHUCOCŒTES LATITANS. _Jen._

PLATE XXIX. Fig. 3.

FORM.—Still more elongated than the _Iluocœtes fimbriatus_, but not
tapering so much to a point posteriorly, the tail being blunter and
more rounded. Greatest depth about one-eleventh of the entire
length: head one-seventh. Head more compressed, its thickness being
only three-fourths of its depth. Nape rather more elevated, and the
profile more sloping, its descent commencing at a more backward
point. Snout equally short and rounded, but much less projecting
over the lower jaw. Gape, intermaxillary, and maxillary, similar:
also the teeth; only the pair of canines above, standing in front of
the series, are smaller; and below, the teeth in front are in two or
more rows. On the fore part of the vomer is one strong tooth, and
apparently one or two other smaller teeth with it; on each palatine
a row, one or two of the anterior ones being stronger than the
others. Eyes very much smaller; their diameter scarcely more than
one-seventh the length of the head; not sufficiently high in the
cheeks to cut the line of the profile: interocular space slightly
convex.

Pieces of the gill-cover on the whole similar, but the branchial
aperture much smaller, the fissure not descending below the level of
the upper part of the pectoral: branchial membrane with six rays.
Skin quite naked, and thickly studded all over with mucous pores.
Also some very large and conspicuous pores in rows on the jaws and
cheeks, but not elevated into cutaneous tubes, excepting the
nostrils, which are tubular.

Dorsal and anal with all the rays articulated, and the greater part of
them simple, but some toward the tail a little branched at their
tips. Caudal not so pointed as in _Iluocœtes_. Pectorals and
ventrals similar, but the latter a trifle longer and broader in
proportion.

Length 4 inc. 7 lines.

COLOUR.—(_In spirits._)—Brown, with the jaws, under part of the head,
and lower half of the cheeks, whitish; also a whitish fascia
extending longitudinally from behind each eye to the upper angle of
the opercle.

_A second specimen_ in the collection is smaller than the above,
measuring only two inches and a half in length. It is in bad
condition, but does not appear to differ, except in having the
anterior canines above but very little developed.

Habitat, Falkland Islands.

Both individuals of this species were taken by Mr. Darwin in the Falkland Islands. “Caught amongst kelp.”—D.

ERRATA.

Page 6, line 2, from the bottom, for _versus apicem_ read _apicem
versus_.

9, — 7, ——, for _versum angulum_ read _angulum versus_.

13, — 4, ——, for _ciliatis_ read _ciliatæ_.

18, — 17, from the top, for _duobus_ read _duabus_.

INDEX.

Acanthoclinus fuscus, Page 92, Pl. XVIII. f. 2.

Acanthurus humeralis, 76

—— triostegus, 75

Achirus lineatus, 139

Agriopus hispidus, 38, 163, Pl. VII. f. 2.

Aleuteres maculosus, 156

—— velutinus, 157

Alosa pectinata, 135, Pl. XXV.

Anguilla australis, 142

Aphritis porosus, 162

—— undulatus, 160, Pl. XXIX. f. 1.

Apistus ——?, 163

Aplochiton tæniatus, 132, Pl. XXIV. f. 2.

—— zebra, 131, Pl. XXIV. f. 1.

Aplodactylus punctatus, 15

Arripis Georgianus, 14

Aspidophorus Chiloensis, 30, Pl. VII. f. 1.

Atherina argentinensis, 77

—— incisa, 79, Pl. XVI. f. 2.

—— microlepidota, 78, Pl. XVI. f. 1.

Balistes aculeatus, 155

—— Vetula, 155

Batrachus porosissimus, 99

Blennechis fasciatus, 84, Pl. XVII. f. 1.

—— ornatus, 85, Pl. XVII. f. 2.

Blennius palmicornis, 83

Callichthys paleatus, 113

Caranx declivis, 68, Pl. XIV.

—— Georgianus, 71

—— torvus, 69, Pl. XV.

Chætodon setifer, 61

Cheilio ramosus, 102

Chromis facetus, 104

Chrysophrys taurina, 56, Pl. XII.

Clinus crinitus, Page 90, Pl. XVIII. f. 1.

Clupea arcuata, 134

—— Fuegensis, 133

—— sagax, 134

Conger punctus, 143

Corvina adusta, 42

Cossyphus Darwini, 100 Pl. XX.

Dajaus Diemensis, 82

Diacope marginata, 12

Diodon antennatus, 151

—— nycthemerus, 150

—— rivulatus, 150

Dules Auriga, 16

—— Leuciscus, 17

Echeneis Remora, 142

Eleotris gobioides, 98

Engranlis ringens, 136

Exocœtus exsiliens, 122

Gerres Gula, 58

—— Oyena, 59

Gobiesox marmoratus, 140, Pl. XXVII. f. 1

—— pœcilophthalmos, 141, Pl. XXVII. f. 2.

Gobius lineatus, 95, Pl. XIX. f. 2.

—— ophicephalus, 97, Pl. XIX. f. 3.

Heliases Crusma, 54

Helotes octolineatus, 18

Hippoglossus Kingii, 138, Pl. XXVI.

Hydrocyon Hepsetus, 128

Iluocœtes fimbriatus, 166, Pl. XXIX. f. 2.

Latilus jugularis, 51

Latilus princeps, Page 52, Pl. XI.

Lebias lineata, 116, Pl. XXII. f. 2.

—— multidentata, 117, Pl. XXII. f. 3.

Mesites alpinus, 121

—— attenuatus, 121, Pl. XXII. f. 5.

—— maculatus, 119, Pl. XXII. f. 4.

Mugil Liza, 80

—— —?, 81

Muræna lentiginosa, 143

—— ocellata, 145

—— ——?, 145

—— ——?, 146

Myxine australis, 159

Ostracion punctatus, 158

Otolithus analis, 164

—— guatucupa, 41

Paropsis signata, 66, Pl. XIII.

Perca lævis, 1, Pl. I.

Percophis Brasilianus, 23

Phucocœtes latitans, 168, Pl. XXIX. f. 3.

Pimelodus exsudans, 111

—— gracilis, 110

Pinguipes Chilensis, 22

—— fasciatus, 20, Pl. V.

Plagusia ——?, 140

Platessa Orbignyana, 137

—— ——?, 138

Platycephalus inops, 33

Plectropoma Patachonica, 11

Pœcilia decem-maculata, 115, Pl. XXII. f. 1.

—— unimaculata, 114

Prionodes fasciatus, 47, 164, Pl. IX. f. 1.

Prionotus Miles, 29, Pl. VI.

—— punctatus, 28

Pristipoma cantharinum, 49, Pl. X.

Psenes ——?, 73

Rhombus ——?, Page 139

Salarias atlanticus, 86

—— vomerinus, 88, Pl. XVII. f. 3.

—— quadricornis, 87

Scarus chlorodon, 105, Pl. XXI.

—— globiceps, 106

—— lepidus, 108

—— ——?, 109

Scorpæna Histrio, 35, Pl. VIII.

Sebastes oculata, 37

Seriola bipinnulata, 72

Serranus albo-maculatus, 3, Pl. II.

—— aspersus, 6

—— Goreensis, 5

—— labriformis, 8, Pl. III.

—— olfax, 9, Pl. IV.

Stegastes imbricatus, 63, 165, Pl. IX. f. 2.

Stromateus maculatus, 74

Syngnathus acicularis, 147, Pl. XXVII. f. 3.

—— conspicillatus, 147, Pl. XXVII. f. 4.

—— crinitus, 148, Pl. XXVII. f. 5.

Tetragonopterus Abramis, 123, Pl. XXIII. f. 1.

—— interruptus, 127, Pl. XXIII. f. 4.

—— rutilus, 125, Pl. XXIII. f. 2.

—— scabripinnis, 125, Pl. XXIII. f. 3.

—— tæniatus, 126

Tetrodon aerostaticus, 152

—— angusticeps, 154 Pl. XXVIII.

—— annulatus, 153

—— implutus, 152

Trigla Kumu, 27

Tripterygion Capito, 94, Pl. XIX. f. 1.

Umbrina arenata, 44

—— ophicephala, 45

Upeneus flavolineatus, 24

—— Prayensis, 26

—— trifasciatus, 25

LONDON: PRINTED BY STEWART AND MURRAY, OLD BAILEY.

-----

Footnote 1:

_Hist. des Poiss._ tom. ix. p. 317. I refer to the quarto edition
throughout.

Footnote 2:

In this and in all other cases, Mr. Darwin has used _Werner’s
Nomenclature of Colours_, by Patrick Syme.

Footnote 3:

I have employed this term to designate the slender curved teeth,
arranged in several rows, which Cuvier calls _en cardes_, or, when
less numerous and rather more developed, _en crochets_. They much
resemble the _prickles_ found on some plants.

Footnote 4:

There are actually only three below in this specimen, but there is
little doubt of four being the normal number, one appearing to have
been lost.

Footnote 5:

The absence of the usual fan has suggested the name of _Arripis_, from
α priv. et ριπις, flabellum.

Footnote 6:

Or at least as represented in the figure in the Histoire des Poissons,
tom. iii. pl. 56.

Footnote 7:

As described by Cuvier and Valenciennes to be the case in the _P.
Brasilianus_.

Footnote 8:

Cuvier in his description, says, of the seventh ray, “fort petit,” but
it is very obvious in this specimen, and scarcely smaller than the
sixth, as above stated.

Footnote 9:

Probably these teeth are liable to be lost or broken off, so as seldom
to occur in exactly the same number and mode of arrangement in two
individuals.

Footnote 10:

As stated by Cuvier and Valenciennes.

Footnote 11:

In the _A. cataphractus_, the body is hexagonal from the gills to a
little beyond the vent; octagonal from this last point to the
termination of the dorsal and anal fins; then hexagonal again to the
end of the tail.

Footnote 12:

Faun. Bor. Amer. Part Third, p. 49.

Footnote 13:

Is it not possible that this may be found to be also the case with
several of the foreign species described by Cuvier, in which the
absence of these teeth has been rather presumed than ascertained from
actual examination?

Footnote 14:

Cuvier seems to have attached much value to the character of teeth on
the palate; but I agree with Dr. Richardson, (_Faun. Bor. Am._ Part
iii. p. 19.) in considering it “of little importance as a generic
character in some families of fish.” And the author last mentioned
notices an instance (exactly analogous to that of the _Aspidophorus
Chiloensis_) in the _Thymallus signifer_, which, he says, “resembles
the common grayling very closely in its general form, but differs from
it in having palatine teeth.”

Footnote 15:

In its general characters it does not depart from the _A.
cataphractus_ of the British seas, anything like so much as the _A.
quadricornis_, and _A. monopterygius_ do.

Footnote 16:

Judging from the figure in the “Voyage de l’Astrolobe (Zoologie),” pl.
10. f. 4.

Footnote 17:

Called by mistake in the plate “magnified scales.”

Footnote 18:

This portion of the fin is not quite correctly represented in the
plate, being made too low, in consequence of the rays having been
broken at their extremities in the specimen figured.

Footnote 19:

Since the above was printed, Mr. Waterhouse has been kind enough to
show me in the museum of the Zoological Society the specimen which he
believes to be the one procured by Mr. Cuming. Unless the characters
are very much altered by age, it is decidedly distinct from the _A.
hispidus_ above described. The general form indeed is the same; but
the skin is perfectly smooth, marked with vertical striæ; the
granulated ridges on the head are less prominent, and the superciliary
ridges without spines. The fin-ray formula is not quite as stated by
Mr. Bennett, who appears, in his computation, to have mistaken the
last dorsal spine for one of the soft rays of that fin, and also to
have over-estimated the number of soft rays in the anal. The formula
is really 18/12; A. 1/9, &c. I have no doubt of Mr. Cuming’s fish
being the true _A. Peruvianus_; whilst the one here characterized as
new is probably the young of a nearly allied species. Mr. Cuming’s
specimen is six and a half inches long.

It may be advantageous to science to mention here, though not
immediately connected with the present inquiry, that another species
of _Agriopus_ in the museum of the Zoological Society, which was seen
by M. Valenciennes during his visit to this country, and referred by
him in the “Histoire des Poissons” to the _A. verrucosus_, proves not
to be that species, but the _A. spinifer_ of Dr. Smith, recently
described by him for the first time in his “Illustrations of the
Zoology of South Africa.”

Footnote 20:

Serræ figuram habens. A πριων.

Footnote 21:

With the exception of a small rough oblong spot, near the posterior
extremity of the left palatine.

Footnote 22:

The third spine is broken, and may have been as long as the fourth.

Footnote 23:

There are actually nine, but one appears to have been lost.

Footnote 24:

Στεγαστης, tector.

Footnote 25:

_G. chrysurus_, Cuv. et Val.

Footnote 26:

This part is exactly as described by Cuvier and Valenciennes in the
_Lichia Amia_, to which genus the present one is so nearly allied.

Footnote 27:

_Lichia Amia_ is represented as having nine; and this forms another
mark of affinity between the two genera.

Footnote 28:

There are scales on the cheeks in _Lichia_, according to Cuvier and
Valenciennes, but I see no appearance of them in this genus.

Footnote 29:

In the _C. trachurus_, the bend begins in a line with the commencement
of the second dorsal, and from its more gradual obliquity, extends
over a space equal to that occupied by nine fin-rays.

Footnote 30:

According to Mr. Lowe, however, the _B. palmicornis_ is common at
Madeira, (see _Proc. of Zool. Soc. 1829_, p. 83), and a specimen
received from him, undoubtedly belonging to that species, is in the
Museum of the Cambridge Philosophical Society.

Footnote 31:

See “Hist. des Poiss.” tom. xii. p. 72, under the species _Gobius
Boscii._

Footnote 32:

_Freycinet Voyage_, (_Zoologie_) p. 286.

Footnote 33:

_Voy. dans L’Amer. Mérid._ Atl. Ichth. pl. 5. fig. 1.

Footnote 34:

Swainson is of opinion that “more than double the number of species of
_Exocœtus_ really exist above those that have been described.”—_Nat.
Hist. of Fishes_, vol. i. p. 299.

Footnote 35:

Thesaurus, vol. iii. pl. 34. f. 3.

Footnote 36:

_Voy. dans L’Amer. Mérid._ Atl. Ichth. pl. 9. fig. 2.

Footnote 37:

Ab απλους simplex, et Χειρων tunica.

Footnote 38:

Valenciennes says, in his preface to the fifteenth volume of the
“Histoire des Poissons,” that none of the _Siluridæ_ have the
subopercle; and that the absence of this bone serves to distinguish
them from _Cobitis_.

Footnote 39:

In the pilchard it is one-fifth.

Footnote 40:

_Excursions in Madeira_, p. 234, fig. 44.

Footnote 41:

In the _E. enchrasicholus_, it is hardly one-fourth of the length,
excluding caudal.

Footnote 42:

I am indebted to Mr. Yarrell for the loan of a specimen of our common
Anchovy for comparison.

Footnote 43:

_Nat. Hist. of Jamaica_, Pl. 246, fig. 2.

Footnote 44:

_Pisces Brazil_, p. 89, tab. L.

Footnote 45:

I notice this circumstance, because Mr. Lowe, in the “Proceedings of
the Zoological Society,” (1839, p. 89.) has briefly described two
species of this fish, which he calls _E. Remora_ and _E. pallida_
respectively, the former having the tongue _smooth_, and the latter
_rough_ in the middle, besides other differences.

The above specimen obtained by Mr. Darwin, as well as two others in
the Museum of the Cambridge Philosophical Society, have the tongue
rough; though in their other characters, especially colour, they would
seem to be Mr. Lowe’s _Remora_. Cuvier, in his “Regne Animal,” appears
to consider the rough tongue as characteristic of the whole genus.

Footnote 46:

_Syst. Ichth._ pl. 96.

Footnote 47:

pp. 13, 14.

Footnote 48:

Surely this cannot be the same as the _T. Honckenii_ of Bloch?

Footnote 49:

This character, though mentioned in the description, is not, however,
represented in the figure. See _Freycinet’s Voyage_ (_Zoologie_),pl.
47. f. 2.

Footnote 50:

_Hist. des Poiss._ tom. 5. p. 356.

Footnote 51:

Ab ιλος limus, et κοιτη cubile.

Footnote 52:

One of these is gone in this specimen, but the socket in which it was
implanted is obvious.

Footnote 53:

A φυκος fucus, et κοιτη cubile.

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TRANSCRIBER’S NOTES

● Fixed typos; non-standard spelling and dialect retained. ● ERRATA was corrected. ● Renumbered footnotes and moved them all to the end of the final chapter. ● Enclosed italics font in _underscores_. ● Enclosed blackletter font in =equals=. ● The caret (^) is used to indicate superscript, whether applied to a single character (as in 2^d) or to an entire expression (as in 1^{st}).