48 
U. S. P. R. R. EXP. AND SURVEYS-ZOOLOGY-GENERAL REPORT. 
The scales are small, cycloid in structure, elongated, sub-elliptical, much longer than deep ; 
rudimentary or very small ones may he observed upon the base of the pectorals and caudal and 
extending to a certain distance along their rays. The upper surface of the head is scaleless, hut 
finely granular. The temporal and facial regions are also granular, whilst over the opercular 
apparatus the skin is perfectly smooth. The lateral line is composed of a series of membranous 
tubes. 
The ground color is blackish brown above, and reddish brown beneath. The dorsal and 
lateral regions are scattered all over with small black spots, which may be observed on the oper¬ 
cular apparatus and cheeks. The inferior regions are unicolor. 
References to the figures. —Plate XVIII, fig. 1, represents Oplopoma pantherina, gomewhat 
reduced in size. Fig. 2, a dorsal scale. Fig. 3, a scale from the abdominal region. 
List of specimens. 
Catalogue number. 
Measurement. 
No. of specimens. 
Locality. 
When collected. 
Whence obtained. 
Nature of specimen. 
275 
Inches. 
22 
1 
Cape Flattery, W. T. 
1855 
Lieut. Trowbridge 
Alcoholic_ 
OPHIODON, Girard. 
Gen. Char. —Mouth deeply cleft; canine teeth on both jaws ; very long patches of velvet-like teeth on the vomer and 
on the palatines. Convexity of preopercle provided with small spines. Minute scattered scales on the head, cheeks, and 
opercular apparatus. No membranous flap above the orbit. Gill openings continuous under the throat; isthmus, therefore, 
absent. Branchiostegal rays six in number. Scales very small, not serrated posteriorly. Lateral line concurrent with the 
dorsal outline. 
Syn. — Ophiodon, Grd. in Proc. Acad. Nat. Sc. Philad. VII, 1854, 133. 
The body and head are more slender than in Ohiropsis ; the mouth more deeply cleft and the 
canine teeth much more developed. The velvet-like teeth constitute longer patches. There is 
one continuous dorsal fin, the spinous portion of which is longer than the soft and articulated 
portion, whilst in Cliiropsis the spinous portion constitutes a separate fin, and is shorter or 
equal to the soft portion. The absence of a membranous flap above the orbit and the presence 
of small spines on the preopercle will likewise distinguish Ophiodon from Ghiropsis. The scales, 
pectinated in one and smooth in the other, will afford the means of discriminating very readily 
between both genera. 
OPHIODOX ELONGATUS, Grd. 
Plate XVIII, Figs. 4-1. 
Spec. Char. —Body lanceolated; head sub-conical, depressed. Mouth deeply cleft; posterior extremity of maxillary 
extending to the vertical of the posterior rim of the orbit. Spinous portion of dorsal fin much longer than the articulated 
one. Anal somewhat longer than soft portion of dorsal. Caudal slightly emarginated posteriorly. Extremities of the 
pectorals nearly even with the tips of the ventrals. Color above olivaceous brown, scattered all over with blackish, 
sub-circular spots. Beneath yellowish. 
Syn. —Ophiodon elongatus, Grd. Proc. Acad. Nat. Sc. Philad. VII, 1854, 133. 
