Latilus jugularis, _Cuv. et Val._ Hist. des Poiss. tom. ix. p. 369. pl.
279.
FORM.—Elongated, with the dorsal line slightly curved, the ventral
nearly straight. Greatest depth contained five times and one-third
in the entire length. Head, which much exceeds the depth, four times
in the same. Profile very convex above the eyes, whence it falls
obliquely to the lips. Snout thick and rounded, resembling that of
the _Red Mullet_: mouth protractile, horizontal, placed at the
bottom of the snout, the commissure just reaching to a vertical from
the anterior part of the orbit. Jaws equal or very nearly so; the
lower one perhaps a very little the longest. Maxillary not widening
at its posterior extremity. A band of velutine teeth in each jaw,
narrowing at the sides as it extends backwards; with an outer row of
longer and stronger ones: in the lower jaw, the velutine band does
not extend beyond the middle of the sides, the carding teeth being
all that are visible. Tongue and palate smooth. Eyes high in the
cheeks; large, and of an oval form; their vertical diameter
three-fourths of their longitudinal; this last equalling one-fourth
the length of the head. Nostrils consisting of two round apertures,
the posterior one largest, the anterior covered by a membranous
flap. Preopercle with the denticles far apart, and not very obvious,
unless the skin be dissected off; the ascending margin rectilineal
and vertical; the angle rounded. Bony part of the opercle
terminating in a flat point, above which are two other smaller
points not so well developed; all the points concealed in the
membrane, and scarcely visible from without: beneath the principal
point, the membrane is prolonged backwards in the form of a broad
flattened bristly point three lines in length. Crown, gill-covers
and cheeks, scaly, but not the jaws; snout scaly, except very near
the lips. Gill-opening large.
Lateral line at first at one-third of the depth, but falling gradually
to one-half. Scales rather small; one taken from immediately above
the lateral line of an oblong form, the length being twice the
breadth, with its free margin finely ciliated, crenated behind with
a fan of nine striæ; on scales taken from other parts the number of
striæ in the fan are more numerous.
One long dorsal fin of nearly uniform height throughout, equalling
about half the depth; only four slender spines, gradually increasing
in length from the first which is very short; the fourth about
three-fourths the length of the first soft ray; soft rays increasing
likewise very gradually to the fourth, which with the next five or
six are highest; the membrane of the fin very delicate; all the soft
rays branched. Vent in a vertical line with the ninth soft ray of
the dorsal. Anal commencing immediately behind it, and answering to
that portion of the dorsal to which it is opposite, terminating at
the same distance from the caudal; only two slender spines, the
first very short; the first soft ray simple, the rest branched.
Space between these two fins and the caudal barely one-eighth of the
entire length. Caudal nearly even. Pectorals moderately long and
narrow, equalling nearly the length of the head; rays branched;
fourth, fifth, and sixth longest. Ventrals a little in advance of
the pectorals, nearly equalling them in length; of a pointed form,
with the third and fourth soft rays longest. In the axilla of the
pectorals a vertical scaly membranaceous lamina.
B. 6; D. 4/28; A. 2/22; C. 17; P. 20; V. 1/5.
Length 11 inc. 5 lines.
COLOUR.—(_In spirits._) Dusky olive on the back and upper part of the
sides, yellowish (probably silvery in the recent state) beneath,
with faint indications of five or six dark transverse bands, similar
to those in the _common perch_. Inside of the ventrals blue.
_Second specimen._—Smaller than the above, measuring six inches and a
half in length, but differing from it in no respect, as regards
form, excepting in having the profile not so oblique, and the snout
in consequence not so obtuse; the jaws also are exactly equal.
Fin-ray formula the same.
COLOUR.—“Beneath brilliant white; head and back clouded with purplish
and carmine red; longitudinal and transverse irregular bands of the
same.”—D. The bands in this specimen amount to eight in number, and
are much more conspicuous than in the larger one above described.
Habitat, Valparaiso, Chile.
The smaller of the two specimens above described was taken by Mr. Darwin
at Valparaiso. The number attached to the larger one has been lost, but
it was probably taken at the same place, where it had been previously
discovered both by M. D’Orbigny and M. Gay. The specimen described by
Valenciennes has one soft ray more in the dorsal, and one less in the
anal, than either of the above; but in all other respects they tally
exactly. As observed in the “Histoire des Poissons,” this species has
many points of resemblance to _Percis_ and _Pinguipes_.
2. LATILUS PRINCEPS. _Jen._
PLATE XI.
[Illustration:
_Fish. Pl. 11._
_W. Hawkins del^t._
_Latilus princeps. ½ Nat. Size._
]
_L. elongatus; corporis altitudine capitis longitudinem æquanti;
dentibus velutinis, serie externâ fortiori, aculeiformi; preoperculo
margine adscendenti recto, leviter denticulato, basali lævi;
operculo mucrone unico; rostro, ossibus suborbitalibus, maxillis,
limbo preoperculi, et interoperculo, nudis; buccis et cranio
squamatis, squamis in vertice spatium angulatum inter oculos
occupantibus; pinnis dorsali analique prælongis; spinis analibus
parvis, gracilibus, primâ minutissimâ; ventralibus accuratè
thoracicis; caudali emarginatâ._
B. 5?; D. 8/26; A. 2/26; C. 15, &c.; P. 18 vel 19; V. 1/5.
LONG. unc. 20. lin. 6.
FORM.—Elongated; the greatest depth equalling the length of the head,
and each contained rather more than four times and a half in the
entire length. Snout short and rather obtuse, the profile bending
downwards in a curve before the eyes. Mouth nearly horizontal, at
the bottom of the snout; when closed, the maxillary, which is not
widened at its posterior extremity, and which is very similar in
form to that of the last species, reaches nearly, but not quite, to
a vertical from the anterior part of the orbit. Lower margin of the
suborbital entire. Teeth forming a velutine band in each jaw, widest
in front, with a row of stronger ones externally: none on the
tongue, vomer, or palatines. Eyes large, and high in the cheeks;
their diameter one-fifth the length of the head. Preopercle with the
angle at bottom rounded; the ascending margin straight, and nearly
but not quite vertical, forming with the basal rather more than a
right angle; the former finely denticulated, but not the latter.
Opercle terminating in one flat point, not projecting beyond the
membrane. The branchiostegous rays appear to be but five in number,
but, the skin being dry, there may possibly be a sixth overlooked.
Cranium, cheeks, and opercle scaly; but not the snout or jaws, or
limb of the preopercle, or interopercle: the scales on the crown are
separated from the naked skin of the snout by a well-defined line,
which forms an advancing angle between the eyes.
Lateral line straight, and continued to the base of the caudal; its
course parallel to the back at between one-fourth and one-third of
the depth. Scales on the body rather small, oblong, longer than
broad, with their free extremities dotted and finely ciliated; the
concealed portion striated finely at the sides, and more deeply at
the base; but all the central portion, including an oblong area of
the same form as the entire scale, without striæ, being only very
minutely roughened or punctured.
One long dorsal, low, and of nearly uniform height throughout,
commencing about in a line with the insertion of the pectorals, and
reaching very nearly to the caudal: eight spines, rather slender,
and very gradually increasing in length, the last being just twice
the length of the first and equalling the distance from the base of
the fin to the lateral line: the soft rays which follow are nearly
even with the last of the spinous till the twenty-fourth, which is
slightly prolonged in a point, and which is followed by two others
shorter than the rest; the ends of the rays are rather worn, but
they appear to have been all branched. Anal also long, commencing at
about the middle of the entire length, or in a line with the sixth
soft ray of the dorsal, and terminating opposite to that fin, to the
last half of which, or rather more than half, it exactly answers;
only two spines, which are so slender and minute, especially the
first, and so closely united to each other as well as to the first
soft ray, as to be scarcely obvious except upon dissection; all the
soft rays, except the first, branched. Space between the anal and
caudal not a tenth part of the whole length. Caudal slightly
notched, or hollowed out, with rows of scales between the rays.
Pectorals pointed, about three-fourths the length of the head, with
the seventh and eighth rays longest; rows of scales at the base
between the rays: in their axillæ a somewhat projecting vertical
scale or lamina, as in the last species. Ventrals immediately
beneath the pectorals, also pointed, but shorter.
COLOUR.—“Above, and the fins, obscure greenish; sides obscure coppery,
passing on the belly into salmon-colour. Pectorals edged with dull
blue. Iris yellowish brown: pupil black-blue.”—D.—The skin has dried
to a nearly uniform brown.
Habitat, Chatham Island, Galapagos Archipelago.
I feel but little hesitation in referring this species, which is one of
the many new ones obtained by Mr. Darwin in the Galapagos Archipelago,
to the genus _Latilus_. The absence of vomerine and palatine teeth
requires it to be placed, according to Cuvier’s views, among the
_Sciænidæ_; in which family, there is no other group besides _Latilus_,
to which it makes any approach. It agrees with that genus in its general
form, and in many of its particularities; it has the same form of snout,
mouth, maxillary, and dentition; the same scaly lamina in the axilla of
the pectorals; the same long undivided dorsal and anal fins, with only
two very small anal spines, so closely united to the first soft ray as
to be easily overlooked. But it may be at once distinguished from the
_L. argentatus_ and the _L. doliatus_, the only two species described by
Cuvier and Valenciennes in the body of their work, by its much more
numerous soft rays in the dorsal and anal fins. From the _L. jugularis_
last described, which resembles it in this respect, it differs in its
thoracic ventrals, shorter head, naked snout and suborbital, and notched
caudal: the profile also falls less obliquely. There is only one
specimen in the collection, a dried skin and rather injured.