1. MOEMYRUS. 219 



other fishes. The Monnyri, besides, accumulate at certain periods 

 such a quantity of fat in the abdominal cavity as well as between 

 the muscles, that their appearance is very much changed — a circum- 

 stance by which Riippell has been induced to establish a nominal 

 species for specimens which either are males, or had lost the fat. 



11. Mormyrus macrolepidotus. 



Mormyi'us macrolepidotus, Peters, Monatsber, Akad. Wiss. Berl. 1852, 

 p. 275. 



D. 23-24, A. 28-32. L. lat. 67. 

 The form of the snout, the eye, and the dentition as in M. cypri- 

 noides ; the pectoral extends to the middle of the ventral. The 

 height of the body is two-sevenths of the total length (without 

 caudal), the length of the head two-ninths. 

 Eastern Africa. 



a. Young. Kiver Rovuma. Presented by Ch. Livingstone, Esq. 



b. Youiag. River Rovuma. Presented by Dr. Kirk. 



12. Mormyrus niger. 

 D. 18-20. A. 26-28. L. lat. 52. 



Snout obtiisely conical, with the mouth terminal, and the upper 

 profile somewhat more curved than the lower ; lower jaw with- 

 out fleshy protuberance, not projecting beyond the upper. Eye 

 small, much shorter than the snout, situated before the middle of the 

 length of the head. Teeth small, deeply notched, few in number. 

 Pectoral longer than the head, extending nearly to the end of the 

 ventral, which is only half as long. The height of the body is two- 

 sevenths oi the total length (without caudal), the length of the head 

 one-filth. Blackish, with indistinct and irregular darkish cross 

 bands ; head, back, and fins black. 



Gambia. 



a. Male, 5 inches long. Purchased of Mr. Dalton. 

 b-c, d. Five inches long. West Africa. 



13. Mormyrus brachyistius. 



Marcusenius brachyistius, Gill, Proc. Acad. Nat. Sc. Phtlud. 1862, 

 p. 139. 



D. 17. A. 27. L. lat. 50 

 Head decuived ; snout convex ; teeth emarginate, few in number. 

 Pectorals shorter than the head, and scarcely extending to the root 

 of the ventrals. The height of the body is nearly equal to the length 

 of the head, and one-fifth of the total (without caudal). (GUI.) 

 West Africa. 



