_C. corpore elongato-ovali; capite grandi, fronte elevato, rostro ex
hoc declivi: caninis quatuor fortibus ad apicem utriusque maxillæ,
ad angulos oris nullis; dentibus lateralibus conicis; interiùs, ad
latera palati, granis plurimis minutis obtusis: preoperculo, limbo
excepto, operculo, et interoperculo, squamatis; preoperculo margine
integro: rostro, maxillis, et suborbitalibus ante oculos, nudis:
lineâ laterali subrectâ: pinnâ dorsali parte spinosa humili, spinis
ad apices laciniatis; molli, heic respondente anali, duplò altiore,
sub-acuminatâ: caudali æquali, solùm radiis exterioribus aliis paulo
longioribus._
D. 12/10; A. 3/12; C. 14, &c.; P. 17; V. 1/5.
LONG. unc. 19.
[Illustration:
_Fish Pl. 20._
_Cossuphus Darwini. ½ Nat. Size._
]
FORM.—Head large: body of a suboval form, but much elongated: greatest
depth at the nape contained about four times and three quarters in
the entire length: head not quite three times and three quarters in
the same. Nape and forehead high, whence the profile descends
obliquely in a straight line to the end of the snout. Jaws equal,
and rather acute: lips fleshy: the end of the maxillary not quite
reaching to a vertical line from the anterior margin of the orbit.
Four very conspicuous, strong, curved, canine teeth at the anterior
extremity of each jaw; those above of nearly equal length, but the
two middle ones rather longer and stouter than the other two; of
those below, on the contrary, the outer ones are the longest, as
well as strongest, being nearly twice as much developed as the
middle ones, which last are of about the same length as, but rather
slenderer than, the outer ones above. The teeth at the sides of the
jaw are short and conical, and not very sharp pointed, forming a
regular series; below they amount to nine or ten on each side;
above, the series may have been originally of the same number, but
in this specimen several appear wanting. Besides these conical teeth
at the sides of the jaws, there is an inner band of small rounded
grains about the size of pins’ heads: the band is broader, and the
grains larger and more distinct above than below: many of them
appear much flattened, and as if ground down by use. Eyes of
moderate size; their diameter about one-seventh the length of the
head; rather high in the cheeks, and nearly equidistant from the end
of the snout and the posterior angle of the opercle. Snout and
suborbital in advance of the eyes, as well as the jaws, naked.
Preopercle large; occupying the posterior half of the cheek,
rectangular, but the angle at bottom much rounded, the ascending
margin vertical, both margins entire; covered with small scales; the
limb rather broad, bounded internally by a slightly raised ridge,
and without scales, but with a few scattered small pores. The
opercle and subopercle form together an irregular oblong, of which
the height is double the length; both are covered with scales larger
than those on the preopercle: the membrane terminates behind in a
blunt angle. The interopercle, which is very distinct, has three
rows of scales on its surface, but none on the margin.
The lateral line is nearly straight throughout its course, the bend
downwards beneath the termination of the dorsal fin being scarcely
perceptible. The tubes of which it is composed are unbranched;
many of them, however, incline upwards at their posterior
extremity towards the back. The scales on the body are rather
larger than those on the opercle: there appear to be upwards of
fifty in a longitudinal line. The free portion of each scale has
its surface finely granulated in the middle, and striated at the
sides.
The dorsal commences rather before one-third of the entire length,
excluding caudal, and occupies a space equalling nearly half the
same; the spinous portion is low, and the spines of nearly the
same length, the first and second only being rather shorter than
the succeeding ones; the membrane between the spines notched: the
soft portion rather pointed, and twice as much elevated as the
spinous. The anal commences beneath the eleventh or twelfth dorsal
spine, and terminates in the same vertical line with that fin; the
soft portion, which answers to the soft portion of the dorsal, is
preceded by three spines, increasing in length to the third, which
is double the first, though itself not above half the length of
the soft rays; these spines are not particularly stout. The space
between the anal and caudal equals one-sixth of the whole length.
Caudal rays nearly even, with the exception of the two outermost
above and below, which being rather longer than the others, give
the fin a slightly crescent-shaped form: the base of the caudal is
scaly, but the scales advance only a very little way between the
rays. Pectorals very little in advance of the ventrals, in length
more than half that of the head, with the second, third, and
fourth rays longest. Ventrals in an exact vertical line with the
commencement of the dorsal, nearly equal to the pectorals, with
the first and second soft rays longest; the spine rather more than
half the length of the first soft ray; the last soft ray united to
the body by a membrane.
COLOURS.—“Centre of each scale pale vermilion red: lower jaw quite
white: a large irregular patch above the pectoral bright yellow:
iris red, pupil blue-black.”—I. The dried skin in its present state
is of a nearly uniform brown.
Habitat, Chatham Island, Galapagos Archipelago.
I have named this species in honour of Mr. Darwin, whose researches in
the Galapagos Archipelago, where he obtained it, have been so productive
in bringing to light new forms. I have referred it to the genus
_Cossyphus_ of Valenciennes, on account of the small rounded grains
behind the principal teeth; but it rather departs from that group in not
having the preopercle denticulated, and in having no scales on any of
the vertical fins, with the exception of a few at the base of the
caudal. In some respects it seems intermediate between that genus and
_Labrus_. It does not appear to be described, though it seems to
approach the _C. reticulatus_ of Valenciennes in many of its characters.
That species however is from Japan.
The canines at the anterior extremity of each jaw are very conspicuous
in this fish, and give it at first sight much the appearance of a
_Dentex_.