eight. In the third, which commences behind the pectoral, and extends in like manner to the
caudal, there are thirty-five. In the fourth, which commences on the breast, immediately behind
the point of attachm ent of the branchial membrane to the isthmus, there are thirty, reckoning
to behind the anal, where it unites with its fellow to form o n e ; between this point and the
caudal there are ten, the serratures of which are rather obsolete. The fourth ^air of ridges
are throxighout their course less sharply serrated than the second and third pairs, and these last
again rather less so than the first or dorsal pair. Between the two ventral ridges, near their
commencement in front of the ventral fins, are six slightly serrated scales (similar to those in
the ridges) forming on the breast a somewhat triangular patch, two single ones standing first,
then four others in pairs. The lateral line, which is catenulated as in A . eataphractus, commences
at the upper angle of the opercle, then bends downwards to take a middle course between
the second and third ridges, which it preserves to the caudal. The first dorsal commences
behind the seventh scale in the dorsal ridges, or at about one-third of the entire len gth ; it is of
the same form as in the A . eataphractus, but contains more rays ; its membrane term inates at
the fifteenth scale, and there are rather more than two scales between it and the second dorsal,
which last is rather shorter aud higher than the first. The rays of the first dorsal are not stouter
than those of the second, nor relatively stouter than those of the A . eataphractus. The rays
of the second dorsal are simple, with the second and third rather longer than the first. The
anal answers to the second dorsal. The pectorals are rounded, and one-fifth of the entire
length. V entrals very narrow, and scarcely more than half the length o f the pectorals.
Position of the vent a little anterior to a line connecting the extremities o f the ventrals.
C o l o u r .— (Jn spirits.) D usky grey above and on the sides, paler beneath ; with four broad transverse
blackish fasci® passing across the back and down the sides as far as the third longitudinal
ridge o f scales. The first fascia is in the region of the first half of the first dorsal; the second
at the commencement of the second dorsal; the third near the end of the second dorsal; the
fourth half way between the end of the second dorsal and the c a u d al; and a little beyond this
there is a faint trace of a fifth fascia. The body is a little mottled in places with spots of the
same dark colour as the fasci®, and the fins, with the exception of the ventrals, are of the same
hue.
Habitat, Chiloe, (West coast of S. America).
The absence of vomerine teeth has been considered by Cuvier as one of the
characters serving to distinguish Aspidophorus ivom Coitus; but as these teeth
are very distinctly developed in the present species, we must rather dwell upon
the large keeled sharp-pointed scales, which envelope the body in a kind of mail,
and, as Dr. Richardson observes,* “ give the Aspidophori a totally different aspect
from the C o ttif Indeed on equally strong grounds as those on which Cuvier has
separated Pinguipes from Percis and Prionotus from Trigla, the present species,
which possesses both vomerine and palatine teeth,f might be made a distinct
* Faun. Bor. Amcr. Part Third, p. 49.
t Is it not possible that this may be found to be also the case with several of tlie foreign species described by
Cuvier, in which the absence of these teeth has been rather presumed than ascertained from actual examination ?
genus from Aspidophorus, or at least considered as one of its subgenera. B ut in
the present uncertain state of our knowledge with respect to the exact value of
this character,* and from the general resemblance of the A . Chiloensis in all its
principal characters to the other species of this genus,| I have not thought this
step necessary.
This species was taken by Mr. Darwin at Chiloe. There are two specimens
in the collection. The second differs from the one above described, only in
having one ray less in the first dorsal, and two more carinated scales in each of
the dorsal ridges. Independently of its having vomerine and palatine teeth as
above noticed, this species will not enter into any of Cuvier’s sections of the
genus Aspidophorus, but combines in itself the characters of his first and third;
the dorsals being separated by nearly three scales, the jaws being very nearly
equal, the rays of the first dorsal not stouter than those of the second, and the
throat being bearded.
P l a t y c e p h a l u s in o p s . Jen.
P . capite longo, leevi, ubique inermi, spinis duobus ad angulum preopercuU brevissimis
(squalibus exceptis ; oculis magnis, arcth propinquantibus : dorso et lateribus fuscis ;
abdomine albido ; pinna dorsali primà litura magna irregulari nigrofuscà posticè
maculatà; dorsali secundà, caudali, et pectoralibus, maculis fuscis parvis; anali et
ventralihus ferl omnino nigricantihus.
B. 7 ; D . 8—12 ; A. 12 ; C. 13, &c. ; P . 19 ; V. 1/5.
L o n g . unc. 16.
F o rm .— Head very much depressed, and rather longer than in most of the species of this g en us; its
length being nearly twice its own breadth, and nearly one-third of the entire length. B readth
of the body a t the pectorals one-seventh of the entire len g th : depth a t th a t point h alf the
breadth. Snout rounded horizontally. Lower jaw longest. Gape reaching to beneath the
* Cuvier seems to have attached much value to the character of teeth on the palate; but I agree with Dr.
Richardson, (Faim. Bor. Am . Part iii. p. 19.) in considering it “ of little importance as a generic character in
some families of fisli.” Aud 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.”
t In its general characters it docs not depart from the A . eataphractus of the British seas, anything like so
much as the A . quadricornis, and A . monopterygius do.