36 



MONOGRAPH OF THE FRESH WATER 



III. 



Body fusiform, 

 elongated. 



/With five ray* 

 to ventral fins. 



corn 



Origin of anal fin opposite to third ray of 

 second dorsal. Pectorals shorter than 

 the head. Vent placed midway between 

 snout and tip of caudal fin. 



C. RICUARDSONII 



Origin of anal fin opposite to sixth ray of 

 second dorsal. Pectorals of same length 

 as head. Vent nearer to snout than 

 to base of caudal fin. 



rays df pectorals liraiiched ; tlieir tip 

 extending to anterior margin of second 

 dorsal. Insertion of ventrals in advance 

 of first dorsal. 





First dorsal very low. Tip of pectorals ex- 

 tending beyond the anterior margin of 

 anal. Insertion of ventrals opposite to 

 the first ray of anterior dorsal. 



Body stout and 

 short. 



C. COGNATC8. 



C. Wn 



C. BAIRDII. 



A second very minute prcnpcrcular spine. 



Origin of anal opposite to third ray of 



second dorsal. Tip of pectorals extend- 

 ing beyond the anterior margin of the C. ALVORDII. 



second dorsal and anal. Insertion of 



ventrals near the lower edge of pectorals 



in advance of anterior dorsal fin. 

 A -.(.-mid and third, exceedingly minute, 



preopcrcular spines. Origin of anal op- 

 posite to fourth ray of second dorsal. 



Tip of pectorals not reaching the anal fin. 



Insertion of ventrals even with the lower 



edge of pectorals in advance of the first 



dorsal fin. 

 Base of pectorals crescendo; their tip cx- 



tending beyond the fifth ray of second 



dorsal and third of anal fins. Insertion C. BOI.EOIDES. 



of ventrals in advance of the anterior 



dorsal, near the lower edge of pectorals. 



Body fusiform 

 and slender. 



With four 

 ry only to 

 il fins. 



C. MEUIDIONAUS. 



A sec I minute |>reo]>ereular spine. Tip 



of pectorals not reaching the anterior 

 margin of second dorsal. Base of pec- 

 torals crescentie. Dorsal fins separated 

 by a free space. 



C. FORMOSUS. 



I!.,-e i,l jieeturals enset'iitic; their ti]i ex- 

 tending beyond the fourth ray of second 

 dorsal and first of anal fin. Insertion of 

 ventrals under the pectorals and in ad- 

 vance of anterior dorsal. 



(\ CRAril.IS. 



Body cylindri- 

 cal, or subcy- 

 lindrical and 



Stout. 



Base of pectorals slightly curved ; their tip ! 

 not reaching the anterior margin 



Insertion of ventrals in advance 

 anterior dorsal and under the middle 

 pectorals. 



(not reacln 

 dorsal. I 

 of anterii 

 of pecton 



C rilASKI.lNII. 



Base <>l -ciitic; their tip not 



reaching the anal fin. Insertion f veti- 

 trals under the upper edge of | 



Hi--- ..i p ctoraln -ir.u^'lii : tlieir tip nut 



iiing the anterior margin of anal. 



Inscrtiiin of vcntruls behind the base of 



pectorals, and in advance of the anterior 



on 



behind the 



C. GOBIOIDES. 



C. \ ISCO8U8. 



^11. id Hilitiilierciiluii*; 



i anil lateral line, rough. 



C I-' \imirii. 



