50 SILURID^. 



is finely serrated along its inner edge. A blackish spot on the origin 

 of the lateral line. 



Kile. 

 a. Adult. Nile. From Dr. E. Riippell's Collection. — One of the 



typical specimens. 

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



Collection. 



e. Adult: skeleton. Chartoum. From Consul Petherick's Collection. 



f. Adult : skeleton. Nile. From Dr. E. lUippell's Collection. 



2. Schilbe mystus. 



Chilby, Soimmi, ii. p. 295. tab. 23. fig. 1. 



Silunis mystus, part., L. Si/st. Nat. i. p. 502 ; Bl Schn. p. 887 ; Gcofr. 



Deseript. Eg. Poiss. pi. 11. fig. 3; Joannis, Guer, Mag. Zool. Itt35, 



pi. 12 (not good). 

 Scbilbe intermedins, Riipp, Fortsetz. Beschreib. Nil-Jische, p. 6. 



auratus, Joamiis, I. c. pi. 5 (not good) *. 



mystus, Cuv. ^- Val. xiv. p. 372. 



B. 9-10. D. 1/6. A. 55-64. P. 1/11. V. 6. Vert. 10/36. 



The height of the body is one-fourth of the total length (without 

 caudal), the length of the head one-fifth ; the greatest width of the 

 head e(]uals its length without snout. The lower jaw is the longer ; 

 the depth of the cleft of the mouth is two -fifths of its width. Nasal 

 barbels shorter than those of the maxillaries, which are half as long- 

 as the head; the posterior mandibulary barbels are three or four 

 times as long as the anterior, and somewhat longer than those of the 

 maxillaries. The diameter of the eye is one-sixth of the length of 

 the head. The dorsal fin is situated entirely before the ventral, and 

 the width of its base equals that of the latter ; its height is less than 

 the length of the head, the length of its spine being three-quarters of 

 the latter ; spine finely serrated posteriorly. The anal fin terminates 

 at a short distance from the caudal, which is deeply forked, with 

 pointed lobes. The pectoral spine is stronger than that of the dorsal 

 fin, and terminates at some distance from the root of the ventral ; it 

 is finely serrated along its inner edge. A large blackish blotch on the 

 origin of the lateral line. 



Nile. 

 a, h, c, d, e, f-k. Adult, half-grown, and young. Lower Nile. 

 I. Half-grown. Nile. From Dr. Riippell's Collection as Schilbe in- 

 ter inedhis. 

 m, n. Half-gro^vn. Chartoum. From Consul Petherick's Collection. 



* M. de Joarmis accuses Eiippell of a double error, viz. of having misstated 

 the number of anal rays of Sch. uranoscopiis and Sck. aurifus. If the French 

 traveller had had a better knowledge of the German language, he would have 

 seen that Eiippell by no means says that Sck. uranoscopiis has 64 anal rays, but 

 that Sch. intcrviedius is only similar to Sch. ura7ioscopus in having 64 rays. As 

 regards the other error, it is quite clear that Riippell intended to compare these 

 two species with Sch. mystus, specimens of which have 54 anal rays, and that by 

 a slip of the pen he wrote aiiritus instead of mystus. 



