slightly striated or veined, and not separated from the cheek by any salient ridge. The other
pieces of the gill-cover taken together are bounded posteriorly by a sinuous and very irregular
margin, the notch in the bone at the upper p art of the opercle being nearly semicircular,
beneath which is an obtuse point, whence the obliquely descending margin first slopes slightly
inwards, then passes outwards to form another blunt point lower down, then slopes inwards
again. The course taken by the margin of the membrane in some measure follows that of the
bone, but the sinuosities and salient angles are more rounded. Cheeks and opei'cle scaly, as
well as the cranium and forehead between the eyes.
The lateral line does not deviate very much from rectilineal. The deflection, such as it is,
m ay be said to commence in a line with the termination of the first dorsal, and to end beneath
the first third of the second dorsal. U p to this point, the scales which cover it are small and
round; but they then begin gradually to enlarge, and to assume a keel terminating posteriorly
in a short spine : these scaly lam in« continue increasing in size till they arrive beneath the last
quarter of the fin, where they are m ost developed ; none of them, however, are very large, and
even here they do not extend over the whole breadth of this part of the tail, nor their own
breadth exceed one-eighth of the greatest depth of the body. After passing the dorsal and
anal fins, they rapidly diminish as they approach the caudal. The entire num ber of laminee
may be set a t thirty-five or thirty-six ; but as it is difficult to fix the exact point where they
commence, it will vary according as the computation is made more or less in advance. The
anterior portion o f the lateral line, bend included, is a little longer than the posterior.
The reclined spine in this species is entirely concealed beneath the skin. The pectorals
are long and falcate, terminating in a sharp p o in t: their length nearly equals th a t of the head,
or about one-fourth of the entire length : when laid back, they reach over the anal finlet, and
very nearly to the commencement of the true anal. The ventrals are attached a little behind
the pectorals, and are only h alf as long. The other fins are much as in the other species of
this genus. The height o f the anterior part of the first dorsal equals exactly half the depth.
The lobes of the caudal are one-fifth of the entire length.
C o l o u r .— N o t n o tic e d in th e r e c e n t s ta te . In spirits; silv e ry o n th e a b d o m e n a n d lo w e r h a l f o f
t h e s id e s, p a s s in g a b o v e t h e m id d le , a n d o n t h e b a c k , in to p a le le a d b lu e , tin g e d w ith g r a y a n d
b r o w n is h : fin s p a le g re y is h b ro w n . N o c o n s p ic u o u s m a r k in g s , e x c e p t th e u s u a l s p o t o n th e
n o tc h o f th e o p e r c le , w h ic h , h o w e v e r , is sm a ll, a n d c o n f in e d e n tir e ly to th e m e m b ra n e .
Habitat, Tahiti.
This species belongs to the second section adopted by Cuvier and Valenciennes
in this genus; or that in which the form of the body resembles that of the
C. trachurus, but in which the laminae on the lateral line only extend over the posterior
portion, the anterior being smooth and simply covered with small scales. B ut
it will not exactly accord with any of the species described by those authors. It
seems to approach most nearly the C. Phimieri; but though the eyes are of
considerable size, they are not quite so large as they are represented to be in that.
There seem, in fact, to be several species characterized by large eyes. Spix and
Agassiz have figured one from America under the name of C. macrophthalmus;
and under the same name Ruppell has figured another from the Red Sea. Both
these, however, appear likewise different from the one here described, at the same
time that their different geographic range renders their identity d. priori improbable.
The present one was taken by Mr. Darwin at Tahiti.
3 . C a r a n x G e o r g i a n u s . Cuv. et Val.
C.aranx Georgianus, Cuv. et Val. Hist, des Poiss. tom. ix. p. 64.
F o r m .—O f an oval compressed form, with the back elevated. Greatest depth one-third o f the
entire length, caudal excluded: thickness not h alf the d ep th : head one-fourth of the entire
length, caudal included. Profile ascending obliquely, and in nearly a straight line, to meet the
dorsal curve. Upper jaw a little the longer. The maxillary, which is truncated and cut nearly
square at its posterior extremity, not quite reaches to beneath the anterior margin of the orbit.
In each jaw a row of about thirty-five teeth, which are small, somewhat cylindrical, set regularly,
nearly equal, and rather blunt at the point; very little trace o f any secondary row, simply
four or six smaller ones behind those in the middle of the upper jaw , and perhaps in the lower
also, but they are not very obvious. A triangular patch of velutine teeth on the vomer, and a
narrow band of the same on each palatine; also on the tongue : these last, however, very closely
shorn. Eyes a little above the middle of the cheek, but exactly half-way between the end of
the snout and the posterior margin of the opercle ; their diameter one-fourth the length of the
head. Preopercle rounded at the angle; its limb separated from the cheek by a slight but not
very salient ridge. Opercle with the notch a t the upper part not very deep; the obliquely
descending margin straight.
The lateral line follows the curvature of the back until it arrives beneath the middle of the
second doreal, at which point it becomes straight, and the scales gradually pass into carinated
spinous laminee. These lam in«, however, are very little developed anteriorly to the last quarter
of that fin ; and even beneath the end of it, where they are largest, they do not extend over
more than h alf the breadth of the tail, nor does their own breadth exceed one-seventeenth of the
greatest depth of the body. The num ber of them is from tw enty to twenty-five, according to the
point a t which the reckoning commences, the transition from the scales to the laminae being very
gradual. The pectorals are falcate and sharp-pointed, and one-fourth of the entire length,
caudal included. The height of the anterior part of the dorsal is contained two and a h alf times
in the depth. The lobes o f the caudal are contained four times and three-quarters in the entire
length.
D. 8—1/27; A. 2— 1/24; C. 17, & c.; P. 20; V. 1/5.
Length 7 inches 6 lines.
C o l o u r .— N ot noticed in the recent state. The colour o f the back and upper part of the sides
appears to have been bluish grey, with steel and other reflections, and was probably very brilliant
in the living fish : belly silvery. No m arkings, except a conspicuous black spot on the
upper part of the opercle.
A second specimen.— Differs in no respect from the above, excepting in having one ray less in the
second dorsal and anal fins.
Habitat, K ing George’s Sound, New Holland.
I entertain not the least doubt of this species being the C. Georgianus of