85. PERCID^ — HADROPTERUS. 
505 
brication takes place after the fashion of the Scitenoids ; instead of 
longitudinal series, they constitute transverse oblique series. As to the 
coloration, it is but imperfectly preserved. Transverse bands of deep 
chestnut alternate with white or yellowish ones. These bands or fas- 
cim are better defined below the lateral line than above it, where they 
are sometimes interrupted. The head is brown, with a vertical black 
streak across the orbits. The fins are yellowish, unicolor, except the 
first dorsal, which is margined with black. During life we imagine this 
fish to be one of the prettiest inhabitants of the fresh waters of this 
continent.” (Girard.) Chihuahua River, Mexico. The types of this spe- 
c’es are lost, but it is doubtless closely allied to A. evides. 
{Diplesion faaciatua Girard, Proc. Acad. Nat. Sci. Phila. 1859, 101.) 
‘ 263* — IIAB>I5©PTrE2£US Agassiz. 
{Hijpohomus Cope: Plesioperca Vaillant.) 
(Agassiz, Amer. Jouru. Sci. Arts, 1854, 305: type Radropteriis nigrofasciatiis Ag.) 
This genus differs from Alvordius only in the absence of the caducous 
ventral plates, the belly being covered with persistent scales, similar to 
those on the sides. (dSpue;^ strong; -Kzepov, fin.) 
a. Anal fin large, not smaller than the second dorsal. 
h. Scales small, more than 75 in the lateral line; body elongate, little compressed ; 
D. XV-15. {Hypohomus* Cope.) 
ySO. H. (Cope) Jor. 
Form elongate ; caudal peduncle slightly contracted ; orbit smaller 
than length of muzzle, 4 in head, excluding the opercular spine ; man- 
dibles shorter than muzzle ; cheeks and operculum covered with small 
scales; scales very small, covering the ventral line; gular region 
smooth ; third dorsal ray longest, fin outline rapidly descending poste- 
riorly; first anal ray below first of second dorsal; caudal fin even. 
Golden-brown above, with a series of small round brown s[)ots nearer to 
the basis of the dorsal fin than the lateral line ; the latter traversed by a 
broad black band, which passes on sides of head around muzzle ; below 
bright citron-yellow ; fins unspotted. Head 4:^; depth C. D. XV-15; 
A. II, 11; Lat. 1. about 85. L. 4^ inches. (Cope.) Headwaters of Ten- 
nessee River. 
(Cottoyaster aurantiacus Cope, Jonrn. Acad. Nat. Sci. Phila. 1869, 211: Hypohomus 
aurantiacus Cope, Proc. Amer. Philos. Soc. 1870, 451 : Hadropterus aurantiacus Jor- 
dan, Man. Vert. 221.) 
bi. Scales large, less than 60 in the lateral line ; body robust, more or less compressed ; 
dorsal XII-12. (Hadropterusi.) 
* Hypulwmus Cope, Proc. Amer. Philos. Soc. 1870, 451: type Cottoyaster aurantiacus 
Cope. (i;;rc», below ; o/fo?, uniform.) 
\ Plesioperca, Vaillant. 
