1907.] 



AFPaCAX SILURID FISHES. 



1085 



mandibular bai'bel nearly as long as nasal, | length of outer. 

 Gill-rakers on first arch not closely set, 16 in number. Clavicles 

 exposed, striated. Dorsal 80, its distance from occipital process 

 ^ length of head, very narrowly separated from caudal. Anal 63, 



Text-fio-. 254. 



Chtrias macromystax. 



very narrowly separated from caudal. Pectoral ^ length of head, 

 the spine strongly serrated on both sides, | the length of the fin. 

 Yentrals much nearer end of snout than caudal. Caudal ^ length 

 of head. Dark brown. 



Total length 205 millim. 



Gambia. 



24. Olarias dumerilii. 



Steindachner, Yerh. zool.-bot. Ges. Wien, xvi. 1866, p. 766, 

 pi. xiii. fig. 8, (fe pi. xiv. fig. 5. 

 Depth of body 6 to 7| times in total length, length of head 4 to 

 4| times. Head 1| to \X times as long as broad, smooth above ; 

 occipital process angular ; frontal fontanelle sole-shaped, about 

 twice as long as broad ; occipital fontanelle smaller, usually ex- 

 tending on the occipital process ; eye very small, its diameter 3 

 times in length of snout, 6 or 7 times in intei-orbital Avidth, Avhich, 

 like the width of the mouth, measures 4 length of head ; band of 

 prfemaxillary teeth 4 times as long as broad ; vomerine teeth 

 conical or subgranular, forming a crescentic band which, in the 

 middle, is a little narrower than the prfemaxillary band ; nasal 

 barbel | to | length of head ; maxillary barbel as long as or a 

 little longer than head, reaching middle or end of pectoral fin ; 



72* 



