50 siluridjE. 



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

 of the lateral line. 

 Nile. 



a. Adult. Nile. From Dr. E. RiippelTs Collection. — One of the 



typical specimens. 

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



Collection. 

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

 /. Adult: skeleton. Nile. From Dr. E. RuppeH's Collection. 



2. Scliilbe mystus. 



Chilby, Sonnini, ii. p. 295. tab. 28. fig. 1. 



Silurus mystus, part., L. Syst. Nat. i. p. 502 ; Bl. Sclin. p. 387 ; Geoffr. 



Descript. Eg. Poiss. pi. 11. fig. 3; Joannis, Guer. Mag. Zoul. 1835, 



pi. 12 (not good). 

 Scbilbe intermedius, liiipp. Fortsctz. Beschreib. Nil-Jische, p. 6. 



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



mystus, Cuv. <$• Vol. 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 equals 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, b, c, d, e, f-Jc. Adult, half-grown, and young. Lower Nile. 

 I. Half-grown. Nile. From Dr. RiippelTs Collection as Schilbe in- 

 termedins. 

 m, n. Half-grown. Chartoum. From Consul Petherick's Collection. 



* M. de Joannis accuses Riippell of a double error, viz. of having' misstated 

 the number of anal rays of Sch. uranoscopus and Sch. auritus. If the French 

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

 seen that Riippell by no means says that Sch. uranoscopus has G4 anal rays, but 

 that Sch. intermedius is only similar to Sch. uranoscopus in having 64 rays. As 

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

 two species with Seh. mystus, specimens of which have ~A anal rays, and that by 

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



