GNATHONEMUS. 49 



mouth on a level with the lower border of the eye, its width equal to the diameter of 

 the eye ; teeth small, bicuspid, 5 in the upper jaw, 6 in the lower ; a slight swelling 

 of the chin. Dorsal and anal fins equally developed and exactly opposed to each 

 other, the former with 31 rays, the latter with 33 ; the fins deepest anteriorly, forming 

 a point behind which the border is feebly concave; their bases equally distant from 

 the caudal fin and from the base of the ventrals, and twice as far from the head as from 

 the caudal fin. Pectoral fin pointed, as long as the head, reaching beyond the base of 

 the ventral, which is about half as long. Caudal fin with pointed lobes, scaly on more 

 than half its extent. Caudal peduncle three times as long as deep, as long as the 

 head. 78 scales in the lateral line, p in a transverse series on the body, — between 

 dorsal and anal fins, 12 round caudal peduncle. 



Brown or dark olive with yellowish bars, two of which enclose a sort of blackish 

 rhomb between the anterior rays of the dorsal and those of the anal fin, which bear a 

 black bar ; a black band on the pectoral and ventral fins and on each lobe of the 

 caudal fin. 



Measurements (in millimetres). 



Total length 140 



„ „ (without caudal fin) 130 



Greatest depth o£ body 38 



Length of head 26 



Width of head 14 



Length of snout 6 



Diameter of eye 6 



Interocular width 8 



Width of mouth 5 



Length of caudal peduncle 25 



Depth of caudal peduncle 8 



Length of pectoral fin 26 



„ ventral fin 13 



This species is based on the figure of a specimen discovered at New Dongola by 

 Baron von Heuglin in 1852, and of which a description has never been given. 

 Mr. Loat has fortunately rediscovered it at Fashoda, on March 23, 1901, and the 

 above description is drawn up from the single specimen obtained by him. 



G. pictns bears a superficial resemblance to the West-African G. moorii, Gthr., to 

 which, from the figure given by Heuglin, I had referred it with doubt (Proc. Zool. 

 Soc. 1898, p. 803). But G. moorii has larger scales and the anal fin originates a little 

 in advance of the dorsal. The two species are perfectly distinct. 



