224 silukim:. 



process and dorsal ^ length of head ; 

 maxillary barbel nearly as long as 

 head ; 20-23 gill-rakers on anterior 



arch ; D. 85-95, A. 65-75 . . .12. C.jaensis, Blgr., p. 242. 

 2. Head not more than 11 times as long as broad. 



a. Maxillary barbel shorter than head ; head 1^—1^ as long as broad, its 



length 4-5 times in total length ; distance between occipital process 

 and dorsal |— j?- length of head ; 10-13 gill-rakers on anterior arch ; 

 D. 65-78, A. 57-64. 

 Maxillary barbel |-| length of head, not 



reaching beyond gill-opening .... 13. C. carsonii, Blgr., p. 243. 

 Maxillary barbel | length of head, reaching a 



little beyond base of pectoral . . . . 14. C. poensis, Blgr., p. 244. 



b. Maxillary barbel as long as or a little longer than head ; distance 



between occipital process and dorsal 2— § length of head, which is 4-5 

 times in total length. 

 Head 1\ as long as broad ; D. 75-84, A. 60- 



70; 10 gill-rakers on anterior arch . . 15. C. submarginatus, Peters, p. 245. 

 Head 14-1J as long as broad ; D. 70-72, 

 A. 50-58 ; 13-15 gill-rakers on anterior 



arch 16. C. lioceplialus, Blgr., p. 246. 



Head slightly longer than broad ; D. 58-60, 



A. 40-42 ; 20 gill-rakers on anterior arch. 17. C. breviceps, Blgr., p. 247. 



c. Maxillary barbel once and \ to twice as long as head ; head 1 1— 1 J as 



long as broad ; 12-15 gill-rakers on anterior arch. 

 Length of head 4-4^ times in total ; distance 



between occipital process and dorsal \—% 



length of head ; distance between ventrals 



and caudal I3-I? that between end of 



snout and ventrals ; D. 70-80, A. 52-60. 18. C. walkeri, Gthr., p. 248. 

 Length of head 5-5^ times in total ; distance 



between occipital process and dorsal §— § 



length of head ; distance between ventrals 



and caudal at least If that between end 



of snout and ventrals ; D. 80, A. 70-73 . 19. C. longior, Blgr., p. 249. 



B. Dorsal and anal in contact with or very narrowly separated from, but not 



adnate to the caudal ; maxillary barbel longer than head. 

 1. Nasal barbel at least as long as head, which is 1J-1| times as lono- as 

 broad; distance between occipital process and dorsal A— J length of head. 

 a. Vomerine teeth conical or subgranular, in a crescentic band. 

 Length of head 3^-41 times in total ; maxil- 

 lary barbel 1^-1 1 length of head ; 20-25 

 gill-rakers on anterior arch ; D. 70-82, 

 A. 55-63 20. C. anyolensis, Stdr., p. 250. 



