220 SILURID^. 



confluent into larger irregular patches ; anal and caudal fins with a 

 white margin. Vert. 17/22. 



Nile. Rivers of the west coast of Africa. 



a. Adult. Egypt. From Dr. Eiippell's Collection. 



h, c-d. Adult and half-grown. Chartoum. From Consul Petherick's 



Collection. 

 e, f. Adult and half-grown. West coast of Africa. 

 g. Adult : skeleton. Nile. From Dr. Eiippell's Collection. 



2. Malapterurus beninensis. 



Murray, EcUnb. Neiv Philos. Journ. new series, 1855, ii. p. 49. pi. 2 ; 

 Clelland, ibid. 1858, viii. p. 177. pis. 1 & 2. 



A. 9. Eye very small, its diameter being one-fonrth of its distance 

 from the upper end of the gill-opening. The length of the head is 

 contained five times and a half or five times and a third in the total 

 (without caudal). The lower jaw slightly prominent. The outer 

 mandibulary barbels extend to, or beyond, the root of the pectoral. 

 Sides of the body with a few small round black spots. Young speci- 

 mens with a broad black cross-band at the root of the caudal ; it is 

 separated by a whitish band from another black one descending from 

 the origin of the adipose fin ; anal without Avhite margin. Old speci- 

 mens nearly entirely uniform black. Vert. 19/21. 



Old Calabar. 



a, b, c, d, e,f-g. Adult, half-gro'mi, and young. — Types of the species. 



3. Malaptenirus afflnis. 

 A. 10. C. 16-17. P. 7-8. V. 6. 



Closely allied to M. beninensis, but with a longer head, the length 

 of which is contained four times and a quarter in the total (without 

 caudal). Eye small, its diameter being one-third or one-fifth of its 

 distance from the upper end of the gill-opening. Jaws subequal 

 anteriorly. The maxillary barbels extend to, the outer ones of the 

 mandible beyond, the gill-opening. Anal fin somewhat longer than 

 high, or as long as high ; caudal as long as the head ; adipose fin as 

 long as anal. Uniform lead-coloured above, whitish below ; caudal 

 with an indistinct whitish margin. 



Old Calabar. 



a. Seven inches long. Presented by W. Carruthers, Esq. 



b. Nine and a half inches long. 



