66 



MOEMYEID^E. 



3. MORMYRUS CASCHIVE. 

 (Plate XII. fig. 2.) 



Mormyrus cascliive, Linnaeus, in Hasselquist, Reise Palasst. p. 440 (1762) ; Cuvier & Valenciennes, 

 Hist. Poiss. xix. p. 227 (1846) ; Marcusen, Mem. Ac. St. Petersb. (7) vii. 1864, no. 4, p. 120 ; 

 Giinther, Cat. Fish. vi. p. 215 (1866), and Petherick's Trav. ii. p. 253 (1869) ;. Boulenger, 

 Proc. Zool. Soc. 1898, p. 815, and Poiss. Bass. Congo, p. 113 (1901). 



Mormyrus longipinnis, Rlippell, Fortsetz. Beschr. n. Fische Ml, p. 7, pi. i. fig. 2 (1832). 



Scrophicephalus longipinnis, Swainson, Nat. Hist. Fish. i. p. 309 (1838). 



Mormyrus geojfroyi, Giinther, 11. cc. pp. 216, 253. 



Mormyrus longirostris, part., Boulenger, 11. cc. pp. 817, 112. 



Depth of body three and three-fourths to five times in the total length, length of 

 head four to five times. Head twice as long as broad in the young, longer in the 

 adult, the upper profile descending in a straight line or feeble curve ; snout produced, 

 about as long as the postocular part of the head in the adult, shorter in the young, its 

 length twice (young) to four times its least depth ; mouth very small, with thick lips, 

 chin slightly swollen, protruding ; teeth small, notched, 5 to 9 in the upper jaw, 8 or 

 10 in the lower; eye small, its diameter five (young) to sixteen and one-third times in 

 the length of the head, once and a half (young) to twice and a half in the interocular 

 width. Dorsal fin with 76 to 90 rays, its base five to seven times as long as that of 

 the anal, and once and one-third to once and three-fifths as long as its distance from 

 the end of the snout, originating well in advance of the vertical of the ventral fins, 

 gradually decreasing in depth posteriorly. Anal fin with 18 to 20 (rarely 21) rays, 

 originating at nearly equal distance from the base of the pectoral and that of the 

 caudal, its longest rays longer than those of the dorsal. Pectoral fin obtusely pointed, 

 three-fifths to three-fourths the length of the head ; ventral one-third to one-half the 

 length of the head. Caudal fin with pointed lobes, for the greater part covered with 

 scales. Caudal peduncle two-fifths to one-half the length of the head, once and a half to 

 twice as long as deep. 100 to 130 scales in the lateral line, ^^ in a transverse series 

 on the body, at the origin of the dorsal fin, gjE^'in a transverse series at the origin of 

 the anal fin, 26 to 30 round the caudal peduncle. 



Hasselquist describes the colour of fresh specimens as glaucous on the back and 

 pale flesh-colour on the belly. Markings are absent. 



This is one of the largest species of Mormyrs, a specimen obtained by Mr. Loat at 

 Biba measuring 750 millimetres. 



M. cascliive appears to be restricted to the Nile, specimens from West Africa, 

 Lake Chad, and the Congo, previously referred to it by me, proving, on renewed 

 examination, to belong to the closely allied M. rume, C. & V. (jubelini, C. & V.), 

 which differs only in the smaller number (20 or 22) of scales round the caudal peduncle. 



