présence of two nasal spines ; but it differs in the roughness of the skin (that
species being described as smooth), and in the greater inequality of the dorsal fin.
Perhaps it may be the same as the species brought from the coast of Chili by
Mr. Cuming, and briefly noticed by Mr. B ennett in the “ Proceedings of the
Zoological Society” (1832, p. 5.), but which this last gentleman did not venture
to describe as new, from the circumstance of its general agreement with the
A . Peruvianus. The principal deviation in Mr. Cuming’s fish from the species
ju st mentioned is stated to have occurred in the number of the fin-rays ; those of
the spinous portion of the dorsal fin being seventeen (one less than in the
A . Peruvianm), while of the soft rays of the anal there were ten (three more than
in the species referred to). Mr. Darwin’s fish agrees with Mr. Cuming’s in the
number of the dorsal spines, but not in that of the soft rays of the anal, which is
eight, being one more than in the A . Peruvianus and two less than in Mr.
Cuming’s ; and it is observable that both the specimens obtained by Mr. Darwin
agree in this particular. Mr. B ennett has not noticed any of the other characters
of Mr. Cuming’s fish.*
One of the most distinguishing peculiarities in the species here described is
the existence of vomerine teeth, which though extremely minute are quite
sensible to the touch. As these teeth are denied by Cuvier to the whole genus,
we have here another instance, similar to that of the Aspidophorus Chiloensis
already mentioned, of the slight value of the character which their presence or
absence affords. Possibly, however, they may disappear in the adult state.
Both Mr. Darwin’s specimens are small, neither equalling two inches; and if
they are immature, which is probably the case, some of the other characters
mentioned in the description, perhaps even the hispidity of the skin, may result
from this circumstance. They must therefore be received with caution until
larger specimens shall have been obtained.
• 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  . hispidm 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 tliat 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 . P erm ianm ; 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 he 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 tliat species, but the A . spini/er of Dr. Smith, recently described by him for the first time in
his “ Illustrations of the Zoology of South Africa.”
F a m i l y .— SC IÆ N IDÆ .
O t o l i t h u s g u a t u c u p a . C u v . e t Val.
Otolithus guatucupa, Cuv. et Val. Hist, des Poiss. tom. v. p. 56. pi. 104.
F o rm .— Elongated, with the back only very slightly elevated beneath the first dorsal: in advance
of that fin the dorsal line is nearly straight, and continuous with the profile. Greatest depth
contained exactly four times and a h alf in the entire length. Head long, contained three and a
h alf times in the same. Lower jaw projecting considerably beyond the upper, and ascending
to meet it. Two strongly developed curved canines at the extremity of the upper jaw ; the rest
of the teeth in this jaw consist of a single row of fine card, nearly equal throughout : in the
lower jaw there are no canines, but one similar row of card, rather stronger than those above,
and not equal, the smallest being in front, and those a t the sides becoming gradually larger
as they extend backwards. No vestige of scales on the lower jaw , lips or maxillary ; but the
suborbital is covered with bright silvery scales. Eye full, and moderately sized ; its diameter
one-fifth the length of the head ; its distance from the end of the upper jaw equalling the
diameter. Margin of the preopercle with a few indistinct striæ and obsolete denticulations.
Opercle with two flat points not much developed. Lateral line very distinct, commencing at
rather less than one-third of the depth, but curving gradually downwards to one-half; continued
to nearly the extremity of the caudal; each scale m arked with an elevated line, from which
there proceed one or two small ramifications on each side.
F irst dorsal triangular, with the first spine very short, the fourth longest, the fifth and
succeeding ones gradually decreasing, the last or tenth being shorter than the first. Second
dorsal almost contiguous, its spine or first ray about equalling the first ray of the first dorsal :
this fin is more than half as long again as the first, and the rays are nearly even. The anal
commences further back than a point opposite the middle of the second dorsal ; there are in
reality two spines in this fin, but the first is so extremely minute as to be alm ost microscopic,
and not seen, unless very carefully sought for ; the second or principal spine is weak, and rather
more than one-third the length o f the soft rays. C audal apparently square, but the rays being
worn at the tips, its exact form cannot be determined. The second dorsal, as well as the anal
and caudal, are partially covered with small scales, which, however, are not very obvious.
Pectorals narrow and rather small, being scarcely more than half the length of the head.
Ventrals placed a little further back, and rather shorter than the pectorals.
B. 7; D. 10—1/20; A. 1/8; C. 17; P. 16; V. 1/5.
Length 9 inc. 9 lines.
C o l o u r .—“ Silvery white, above iridescent with violet purple and blue.”— D . Mr. Darw in has not
noticed the dark transverse lines, which descend from the back obliquely forwards, as repre