GNATHONEMTJS. 



55 



4. GNATHONEMUS LONGIBARBIS. 

 (Plate X. fig. 2.) 



? Mormyrus peter sii, part., Giinther, Petherick's Trav. ii. p. 256 (1869). 

 Mormyrus longibarbis, Hilgendorf, Sitzb. Ges. nat. Fr. Berlin, 1888, p. 78. 

 Gnaihonemus longibarbis, Boulenger, Proc. Zool. Soc. 1898, p. 802. 



Body strongly compressed, its depth four to four and a half times in the total 

 length ; length of head four and one-fifth to four and a half times in the total length. 

 Head longer than deep, a little more than twice as long as broad, with feebly curved 

 upper profile ; snout about two-thirds the length of the postocular part of the head, 

 twice and one-third or twice and a half the diameter of the eye, which is contained 

 six to seven times in the length of the head; interorbital width about twice the 



Fig. 8. 





■■■■■■■■:..-;,.■■■ . ■ ■■■..■■■■■■■■■. ■ 



Gnaihonemus longibarbis, type specimen in Berlin Museum. Reduced to -j&-. 



diameter of the eye ; mouth very small ; chin with a long, cylindrical, pointed dermal 

 appendage, as long as or a little longer than the snout, directed forwards ; teeth small, 

 notched, 3 or 5 in the upper jaw, 4 or 6 in the lower. Dorsal fin with 22 to 25 rays, 

 its length about one-half or two-fifths its distance from the head and equal to or a little 

 greater than its distance from the caudal fin. Anal fin with 28 to 31 rays, originating 

 a little in advance of the dorsal, its distance from the ventral fin greater than that from 

 the caudal. Pectoral fin obtusely pointed, about two-thirds the length of the head and 

 extending to the base of the ventral, which is only about half as long. Caudal fin 

 nearly entirely scaly, with pointed lobes. Caudal peduncle two-thirds to three-fourths 

 the length of the head, twice or twice and one-third as long as deep. 58 to 64. 

 scales in the lateral line, y^9 i n a transverse series on the body, ^q- in a transverse 

 series between dorsal and anal fins, 10 or 12 round caudal peduncle. 



