1907.] 



AFRICAN SILURID FISHES. 1067 



II. Ventral fins once and \ to twice as distant from root of caudal as from end 

 of snout, or nasal barbel at least as long as head ; bead smooth or verj"- feebly 

 granulate above ; less than 30 gill-rakers on anterior arch. 



A. Dorsal separated from caudal by a space at least equal to diameter of eye ; 



nasal barbel shorter than head. 



1. Maxillary barbel shorter than head ; head 14-lg^ as long as broad, its length 



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

 |— f length of head; 10-13 gill-rakers on anterior arch; D. 65-78, 

 A. 57-64. 

 Maxillary barbel f-^ length of head, not reaching 



beyond gill-opening 12. C. carsonii Blgr. 



Maxillai-y barbel f length of head, reaching a little 



beyond base of pectoral 13. C. foensls Blgr. 



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



occipital process and dorsal |-f length of head, which is 4-5 times in 

 total length. 

 Head IJ as long as broad ; D. 75-84, A. 60-70 ; 10 



gill-rakers on anterior arch 14. C. suhmarginatus Peters. 



Head 1^-1* as long as broad ; D. 70-72, A. 50-58 ; 



13-15 gill-rakers on anterior arch 15. (7. lioceplialus Blgr. 



Head slightly longer than broad ; D. 58-60, A. 40-42 ; 



20 gill-rakers on anterior arch 16. C. hreviceps Blgr. 



3. Maxillary barbel once and ^ to twice as long as head ; head l^^lg^ 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 \-h: length of head ; 



distance between ventrals and caudal l^lf that 



between end of snout and ventrals; 1). 70-80, 



A. 52-60 17. C. walkeri Gthx. 



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



occipital process and dorsal f-i length of head; 



distance between ventrals and caudal at least If that 



between end of snout and ventrals ; D. 80, A. 70-73.. 18. C. longior Blgr. 



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



adnate to the caudal ; maxillary barbel longer than head. 



1. Nasal barbel at least as long as head, which is l|^-li as long as broad; dis- 



tance between occipital process and dorsal ^^ length of head. 

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

 Length of head 3i-4g- times in total ; maxillary 

 barbel li-lf length of head ; 20-25 gill-rakers on 



anterior arch : D. 70-82, A. 55-63 19. C. angolensis Stdr. 



Length of head 4-4j times in total ; maxillary barbel 

 2-2|- length of head ; 17-22 gill-rakers on anterior 



arch; D. 78-87, A. 55-67 20. C. hi/tJiipogon SauY. 



Length of head 4-45 times in total ; maxillary barbel 

 l^-lf length of head ; 14-15 gill-rakers on anterior 

 arch ; D. 65-78, A. 55-62 ; occipital process much 



longer than broad 21. C. alluaudi Blgr. 



Length of head 4|-5 times in total ; maxillary barbel 

 Ig— 2 length of head ; 16-18 gill-rakers on anterior 



arch; D. 82-91, A. 68-72 22. C. werweH Blgr. 



h. Vomerine teeth granular, in a fan-shaped 

 patch ; length of head 4 times in total ; 

 maxillary barbel 1\ length of head ; 15 

 gill-rakers on anterior arch; D. 80, 

 A. 63 23. C. macromystax Gfhx. 



2. Nasal barbel shorter than head. 



a. Length of head 3i— 4|^ times in total ; distance between occipital process 

 and dorsal |-| length of head ; D. 60-72, A. 44-55. 

 Pectoral spine strongly serrated on both sides ; 12-15 



gill-rakers on anterior arch 24. C. dumerilii Stdr. 



Pectoral spine feeblj^ serrated; 20 gill-rakers on 



anterior arch 25. C. liheriensis Stdr. 



Proc. Zool. Soc— 1907, No. LXXI. 71 



