198 REPORT OF STATE GEOLOGIST. 



ANALYSIS OF THE GENERA OF CYPRINID^ FOUND IN INDIANA. 



1. Dorsal of not more than ten rays. 



A. Alimentary canal more than twice as long as the body. Peri- 

 toneum usually black, 

 a. Alimentary canal six to nine times as long as the body and 

 coiled around the air bladder. , Campostonia, p. 199. 

 aa. Alimentary canal shorter, but more than twice the length 

 of Ihe body; wholly below the air bladder, 

 b. Teeth, 5-5 or 4-5 ;* beginning of the dorsal behind 

 the ventrals ; scales, sixty or more along the lateral 

 line. 



c. No pseudobranchise present ; lateral line complete. 



Oxygeneum, p. 200. 

 cc. Pseudobranchise present ; lateral line incomplete. 



Chrosomus, p. 200. 

 bb. Teeth, 4-4; beginning of dorsal over the ventrals ; not 

 more than fifty scales along the lateral line. 



d. Rows of scales in front of dorsal fewer than fifteen. 



Hybognathiis, p. 201. 

 dd. Rows of scales in front of dorsals more than 

 twenty. Phnephales, p. 202. 



AA. Alimentary canal short, not more than twice the length of the 

 body; peritoneum usually pale. 

 e. Teeth in the main row, 4-4 ; anal rays rarely as many as 

 twelve, 

 f Maxillary without barbels ; premaxillaries protractile 

 (as shown by a furrow between the upper lip and 

 forehead), 

 g. Scales along lateral line not more than fifty. 



h. Mandible interopercle, and suborbital with 

 externally visible cavernous areas (like sil- 

 very cross-bars) ; dorsal over ventrals. 



Ericymha, p. 203. 

 hh. Mandible, etc., without cavernous areas. 



i. Lower lij^ thin, not developed as a fleshy 



lobe on each side. 



j. Teeth, 4-4, and about twenty-eight 



scales in front of the dorsal ; a black 



spot on front of dorsal and another at 



the base of the tail. Cliola, p. 204. 



■■' This means that there are five teeth on each pharyngeal bone, or four on one and five 

 on the other. 



