18. BRACHYALESTES. 315 



and I have examined several specimens in which the second tooth 

 was only slightly dislodged, and in one case it occupied its original 

 place on one side and was pushed backwards on the other. 



2. Brachyalestes ruppellii. 

 D. 10. A. 17*. L. lat. 30. • L. transv. 5 X 



The height of the body is one-third, or a little less than one-third, 

 of the total length (without caudal), the length of the head one- 

 fourth, or, in younger examples, somewhat more than one-fourth. 

 The origin of the dorsal fin is a little behind that of the ventral, 

 midway between the extremity of the snout and the root of the cau- 

 dal. The pectoral terminates close to the ventral. Bright silvery, 

 with a very indistinct blackish humeral spot ; caudal spot absent or 

 very indistinct. Iris golden, with a broad black ring; sometimes 

 entirely black in specimens preserved in spirits. 



Upper Mle. 



a-c. Adult (6| inches long) and half-grown. Chartoum. From 

 Consul Petherick's Collection. 



This species is scarcer than its congener from the same river, to 

 which it is extremely similar ; nevertheless there can be no doubt 

 that it is specifically distinct, having constantly one anal ray more, 

 a peculiarly dark eye, and a somewhat longer pectoral fin. It is 

 perfectly evident to which of the two species the name of B. nurse 

 must be applied : Ruppell states -^ anal rays in his description (and 

 when we compare this with the figure, we find that he counted the 

 middle simple ray as first, and the last as two), and the pectoral is 

 represented short, both of which characters agree with our B. nurse. 

 Thus, the question remains, whether our fish be identical with the 

 Guile of Joannis and Valenciennes. The distinctive characters 

 brought forward by the former are of so trivial a nature, that they 

 need no further comment; whilst we have shown above that the 

 character of a triple series of teeth, assigned to the Guile by Valen- 

 ciennes, is peculiar to the old age of B. nurse. Moreover Joannis 

 counted 16 anal rays, fortunately explaining the way in which he 

 obtained that number, and which agrees with that adopted by myself, 

 whilst Valenciennes states even one ray less ; this is sufficient proof 

 of the correctness of the opinion that the Guile of the French natu- 

 ralists is synonymous with Kiippell's Nurse. 



'6. Brachyalestes longipinnis. 

 D. 10. A. 21-22. V. 8. L. lat. 26. L. transv. 5/2|. Vert. 16/17. 

 The height of the body is contained twice and two -thirds or twice 

 and three-fourths in the total length (without caudal), the length 



* This number is obtained by counting the rays in the same manner as in 

 B. nvrsc, namely, by counting the first rudimentary ray, by taking the longest 

 simple one as third, and by reckoning the last, which is split to the base, as two. 



