36 
U. S. P. R. R. EXP. AND SURVEYS-ZOOLOGY-GENERAL REPORT. 
situated in advance of the base of the pectoral fins ; and in being provided mostly with velvet¬ 
like teeth, and sometimes with canine teeth intermingled. 
The representatives of this family are all of marine habits ; those recorded below are new to 
science, and peculiar to the fauna of our western coast. 
Like most of the percoids, they are esteemed upon European tables. How far the species 
described below is savorous, the settlers of western America alone are prepared to tell. Its 
compressed and thin body may not be deemed worthy of the trouble of culinary skill, unless it 
should reach a larger size than we at present know. 
HETEROSTICHUS, Girard. 
Gen. Char. —Body very compressed, and thin posteriorly. Mouth moderate, lower jaw longest ; canine teeth upon the 
jaws, velvet-like teeth upon the vomer and palatines. Opercular apparatus without either spines or denticulations. Branchi- 
ostegal rays six in number. One continuous dorsal fin, occupying nearly the whole length of the back, with its upper outline 
variously depressed ; soft portion much shorter than the spinous. Anal fin very long, provided anteriorly with but few spinous 
rays, and extending posteriorly near the base of the caudal. Caudal fin slender. Scales very small. Lateral line arched above 
the pectorals. 
Syn. — Heterostichus, Grd. Proc. Acad. Nat. Sc. Philad. VII, 1854, 143. 
The most prominent feature of this genus, which is allied to Percis, Pinguipes, and Per- 
cophis, consists in its very compressed body ; also in the development and structure of its dorsal 
fin. The latter originates near the occipital region, and extends to near the base of the caudal. 
The line described by its upper edge is undulating, owing to the diversity of the rays composing 
it. The extent of the anal fin, as also the reduced size of the scales, may likewise rank amongst 
characters of no minor importance. 
So far we are acquainted with but one species of this genus, a description of which is here 
offered, accompanied by a very accurate figure. 
HETEROSTICHUS ROSTRATUS, Grd. 
Plate XIII. 
Spec. Char. —Head conical, tapering towards the snout; lower jaw longest. Canine teeth small and slender, disposed 
upon one single row. Caudal fin small, posteriorly emarginated. Anal fin very long, deepest posteriorly. Articulated rays 
of dorsal highest. Seales minute. Yellowish brown, with irregular transverse blackish blotches. A postocular, triangu¬ 
lar, blackish brown blotch. 
Syn.— Heterostichus rostratus, Grd. Proc. Acad. Nat. Sc. Philad VII, 1854, 143. 
The head is rather small and sub-conical, continuous with a compressed body, anteriorly deep, 
tapering posteriorly to a caudal peduncle, the least depth of which is about the fourth of the 
greatest depth. The latter, measured across the pectorals, is contained five times in the entire 
length. The greatest width, anteriorly, is about the half of the greatest depth: fig. 2 will give 
an idea of its gradual decline posteriorly. The head constitutes about the fourth of the total 
length, or a little less ; its upper outline is very much depressed and slighly concave. The 
snout being elongated, and the mouth cleft almost to the anterior rim of the orbit. The mouth 
is rather above the medium size, and might almost be called large. The lower jaw is the 
longest, and protrudes beyond the upper one. The posterior extremity of the maxillaries reach 
a vertical line passing in advance of the pupil, and are toothless. The premaxillaries are broadly 
developed, bearing exteriorly one row of conical and slender teeth, and inwardly an oblong 
patch (one on each, and closely approximating) of velvet-like teeth ; a patch of similar teeth 
