12 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY—II. 
Seales about 5-50-6. Fin-rays:—dorsal IX (or VIII), 12; anal I, 7 
or 8. 
Spinous dorsa! low and short, the spines about equal, the longest less 
than half the height of the soft rays of the second dorsal. The bases of 
the two fins are about equal, and they are slightly connected by mem- 
brane. 
In the male specimen, the dorsal spines are somewhat’ swollen and 
white at their tips, but rather less so than is usual in the genus. 
Color partly obliterated by the alcohol. The male is rather dark, not 
spotted, striped, or banded. ‘The female is somewhat mottled, and has 
about six cross-blotches on the back. The second dorsal, caudal, and 
pectorals are barred with black and pale, the caudal especially so. The 
other fins are black in the male; in the female, the lower fins are pale. 
A large black humeral spot. Length 23 inches. 
This species is technically an Htheostoma, of which genus it possesses 
the general form, fin coloration, and dorsal fin. It has the mouth of 
Pecilichthys, the scaly head of Nanostoma, with a condition of the lat- 
eral line intermediate between Pecilichthys and Nanostoma. The other 
species of Htheostoma have the head naked. 
The specific name fontinalis was used by Prof. Putnam on the suppo- 
sition that this species is identical with that described under the same 
name by Rafinesque. 
ANALYSIS OF GENERA OF ETHEOSTOMATIDA. 
The following analytical synopsis gives the characters at present as- 
signed to the genera of Htheostomatide admitted in this paper. The 
categories recognized are very closely related, but are susceptible of 
definition :-— 
*, Lateral line complete; body much elongate, subeylindrical, pellucid, with at least 
the entire ventral region naked: 
a. Body entirely naked, except the caudal peduncle and the lateral line; dorsal fins 
high, well separated, equal to the anal fin and to each other; a single anal 
spine; head entirely scaleless; mouth large, with vomerine teeth, the up- 
per jaw subprotractile: =. << <4. -.... -teendaet-neeceamaes AMMOCRYPTA, 1. 
aa. Body covered above with small thin imbedded scales, the ventral region entirely 
naked, the dorsal scales obscure but present ; dorsal fins small, wide apart ; 
two anal spines; cheeks and opercles scaly ; mouth large, with vomerine 
teeth, the upper jaw subprotractile ...--....--..--.---.- PLEUROLEPIS, 2. 
**. Lateral line complete ; body less elongate, entirely scaly, or with definitely naked 
areas on throat, neck, or ventral line: 
t. Second dorsal not larger than spinous dorsal, and little, if any, larger than anal; 
the dorsal fins distinct, the first the longer and usually the larger; body 
little compressed ; two distinct anal spines (except in Alvordius peltatus, 
a species of uncertain affinities): 
