56 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY—II. 
have been brought forward to distinguish Algoma. Cliola Grd. seems 
to be equivalent to Episema Cope & Jordan, the dentition and position 
of the dorsal! being the same in both. Notropis Raf. is revived in place 
of Alburnellus, Notropis atherinoides being evidently Alburnus rubellus 
Ag., or some closely related species. Sarcidium I unite with Phenaco- 
bius without hesitation, on examination of the types of each. Pho- 
togenis Cope I retain for the present, rather from the fact of the utter 
dissimilarity of the species with those of Nototropis than from ability to 
show any good distinctive characters. It is perhaps questionable 
whether the development of the peculiar satin-white pigment, which is 
found in the fins of the males in spring in every species of Photogenis 
and Cyprinella known in life, and in no species of any other group (ex- 
cept Codoma, a very near affine of Cyprinella), may not be a true generic 
character. 
In the genera proposed by Girard, I consider the species first men- 
tioned as the intended type, as I believe it is a known fact that Girard 
himself so considered it. Some species referred to certain genera will 
be found not to agree with the characters here given. Several such 
species need a reéxamination. It may be premised that the present 
arrangement is to be considered merely temporary, as a step from 
the present condition of chaos toward solid ground. 
*. Dorsal fin without a strong developed spine; ventral fins not decurrent on the abdo- 
men; dentary bones slender, arched, and widely separated 
except at their symphysis; opercular and mandibular bones 
without externally visible cavernous chambers; pharyngeal 
teeth well developed: 
+. Air-bladder suspended in the abdominal cavity and surrounded by many conyolu- 
tions of the long alimentary canal (Campostomine) : 
a. Teeth in the principal row 4-4, with oblique grinding surface and no hook; 
mouth inferior; lips sheathed; upper lip protractile; ali- 
mentary canal six to nine times length of body; sexual dif- 
ferences very great; males strongly tuberculate, 
CAMPOSTOMA, lL. 
tt. Air-bladder contiguous to the roof of the abdominal cavity and above the aliment- 
ary canal (Leuciscine): 
{. Rudimentary dorsal ray separated from first developed ray by membrane ; head 
short, mouth small, inferior; upper jaw protractile; teeth 
4-4, with grinding surface, not strongly hooked; males with 
the head tuberculate : 
b. Alimentary canal elongate, two or three times length of body ; teeth scarcely 
hooked; jaws normal: 
ce Lateral.line incomplete. -.-2.)-. 2.2. 2522 2 Se oon cole. Jee LIMEPHABES 2. 
ce. Lateral line complete “72S tit esoee eee ee ce eeeeeee HyYBORHYNCHUS, 3. 
bb. Alimentary canal short, about as long as body; teeth hooked; jaws with 
spoon-shaped bony expansions, somewhat as in Tetrodon, 
COCHLOGNATHUS, 4. 
