36 MORMTEIDiE. 



2. PETROCEPHALUS BOVEI. 

 (Plate VIII. fig. 1.) 



Mormyrus hovel, Cuvier & Valenciennes, Hist. Poiss. xix. p. 283 (1846) ; Griinther, Petherick's 

 Trav. ii. p. 255 (1869) ; Steindachner, Sitzb. At Wien, lxi. i. 1870, p. 553. 



Petrocephalus bovei, Marcusen, Bull. Ac. St. Petersb. xii. 1854, p. 14 ; Boulenger, Proc. Zool. Soc. 

 1898, p. 789. 



Depth of body three to three and a half times in the total length, length of head 

 four to four and a half times. Head as long as deep, about twice as long as broad ; 

 snout very short, one-seventh to one-fifth the length of the head, rounded, projecting 

 beyond the mouth ; mouth situated below the eye, its width two-sevenths to one-fourth 

 the length of the head; teeth bicuspid, 10 to 14 in the upper jaw, 16 to 20 in the 

 lower ; nostrils close together, on a level with the lower border of the eye ; eye large, 

 longer than the snout, its diameter three and a half to four and a half times in the 

 length of the head, once and one-fourth to once and three-fifths in the interocular 

 width. Dorsal fin with 22 to 26 rays, originating above the fifth to eighth ray of the 

 anal, its length once and a half to twice in its distance from the head; anterior rays 

 longest, the fin pointed in front. Anal fin with 30 to 35 rays, equally distant from 

 the base of the ventral and from the base of the caudal, or a little nearer the latter; 

 the anterior rays longest, the fin falcate in females, less distinctly so in males. 

 Pectoral fin pointed, two-thirds to four-fifths the length of the head, nearly twice as 

 long as the ventral, and extending beyond the vertical of the base of the latter. 

 Caudal fin scaled at the base, with pointed lobes. Caudal peduncle twice and a half 

 to three times as long as deep, two-thirds to four-fifths the length of the head. 38 to 

 43 scales in the lateral line, yx^ in a transverse series on the body, q£^ ln a transverse 

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



The coloration is uniform silvery, the back a little darker, the fins white. A sketch 

 taken by the late P. Delhez on the Senegal shows a little pink at the base of the 

 pectoral and caudal fins ; the iris is silvery and the pupil orange. 



This species does not appear to exceed a length of 120 millimetres. 



Originally described from specimens obtained by Geoffroy St.-Hiiaire and by Bove 

 in the Lower Nile, the species has since been found in the Senegal and in the Gambia. 

 I have examined the following specimens, preserved in the British Museum : — 



1 Kafr-el-Zayat, Eosetta branch of Nile. - Loat, 14.11.99. 

 10 Kaedi, Senegal.— Delhez, 1899. 

 1 McCarthy Id., Gambia.— Budgett, 1900. 



I have also been able to examine the type specimens, eleven in number, badly 



