1915.] 



NATURAL SCIENCES OF PHILADELPHIA. 



227 



occipital process, moderate. Occipital process triangular, extends 

 about first fourth in predorsal space. 



Gill-openings large, extend forward about first f in head. Gill- 

 rakers 1+9, lanceolate, about equal filaments or eye in length. 

 Shoulder-girdle, within gill-opening, with a well-developed process 

 opposite origin of pectoral spine. Branchiostegals moderate. 



Body covered with smooth skin. L. 1. simple, slopes from shoulder 

 till midway along side of trunk, though not continued beyond caudal 

 peduncle. 



Dorsal inserted slightly behind first third in combined head and 

 trunk length, free from caudal behind. Anal origin nearer caudal 

 base than snout tip, also free from caudal behind. Caudal elongate, 

 rounded behind. Pectoral If to ventral, spine with rough serrae 



^1 ^^^-f^^ 



-*->«'C4!:^^f'« 



Fig. 7. — Clarias duchaillui Fowler. (Type.) 



along both edges, anterior retrorse, and posterior only on terminal 

 portion of edge. Ventral small, inserted well back, and reaches 

 slightly beyond anal origin. Vent close before anal. 



Color in alcohol uniform dull brownish, fins and lower surface of 

 head all paler. Iris dull slaty. Barbels brownish. 



Length 97 mm. 



Type, No. 8,568, A. N. S. P. Gaboon Country, West Africa. 

 P. B. Du Chaillu. 



Also Nos. 8,569 to 8,574, A. N. S. P., paratypes, same data. These 

 show: Head 4f to 4f ; depth 6h to 6f ; D. 70 to 78; A. 56 to 62; 

 snout 2| to 2* in head; eye 7 to 8; mouth width 2 to 2|; inter- 

 orbital If to 1|; length 76 to 92 mm. 



This species is apparently allied with Clarias submarginatus 



