56 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY ^11. 



have beeD brought forward to distinguish yl^^oma. Cliola Grd. seems 

 to be equivalent to JEpisema Cope & Jordan, the dentition and position 

 of the dorsal being the same in both. Notro;pis Eaf. is revived in place 

 of Alburnellus, Wotropis atJierinoides being evidently Alburnus ruhellus 

 Ag., or some closely related species. Sarcidium I unite with Phenaco- 

 Mus without hesitation, on examination of the types of each. Fho- 

 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 reexamination. 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 boues slender, arched, and widely separated 

 except at their symphysis; opercular and mandibular bones 

 ■without externally visible cavernous chambers ; j)haryngeal 

 teeth well developed : 

 t. Air-bladder suspended in the abdominal cavity and surrounded by many convolu- 

 tions of the long alimentary canal {Campostomince) : 

 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, 1. 

 tt. Air-bladder contiguous to the I'oof of the abdominal cavity and above the aliment- 

 ary canal {Leudscince): 

 i. 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 : 

 1). Alimentary canal elongate, two or three times length of body ; teeth scarcely 

 hooked; jaws normal: 



c Lateral line incomplete Pimephales, 2. 



ec. Lateral line complete Hyborhynchus, 3. 



6&. Alimentary canal short, about as long as body ; teeth hooked ; jaws with 

 spoon-shaped bony expansions, somewhat as in Tetrodon, 



COCHLOGNATHUS, 4. 



