11. LAUKO. 47 



portion rectangularly bent inwards towards the symphysis. Number 

 of vertebra) in L. niloticus 2G abdominal and 15 caudal ; in L. fors- 

 Z:«Za 2.'i abdominal and 10 candal. The inward-directed ridgos of 

 the humoral arch arc much dilated, rendering the pharyngeal pas- 

 sage very narro-w. 



Si/nopsis of the S2Jecies. 



A. L. lat. less tlian oO. 



1. African species. 



a. More than tliirtoon dorsal rays, p. 47. 



b. Thirteen dorsal rays, p. 50. 



2. Indian species. 



a. More than tliirteen dorsal rays, p. 51. 

 h. Tlurteen dorsal rays, p. 57. 



B. L. lat. more than 50, p. 59. 



A. L. hit. less than 50. 



1. African, species. 



a. More than thirteen dorsal rays. 



1. Labeo niloticus. 



? Cyprimis rufesceus, Hasselq. Jieisc nach Palfpst. 1702, p. 435. 

 Cypriuus niloticus, Forsk. Descr. Anim. p. 71. no. 104 ; Geoffr. Descr. 



Eg. Poiss. pi. 9. fig. 2 (not good), 

 Labeo niloticus, Cuv. Hctjne Anim. 



Chrondrostoma dembensis, Cuv. 4'" Val. xvii. p. 398 (not Jilipp.). 

 Labeo A'ulgaris. Heckcl, in Russegyc/s Heisen, ii. 3. p. 303, taf. 20. 



tig 3. 



D. 16-lt>. A. 8. L. lat. 40-43. L. transv. g. Vert. 26/15. 



Mouth rather broad. Lips thin, fringed, with an inner fold in 

 their entire circumference, more distinct on the upper lij) than on 

 the lower. Snout obtuse, moderately projecting, with a very indis- 

 tinct lobe on each side ; maxillary barbie minute, hidden in a lateral 

 groove. Eye of moderate size, not much smaller thah a scale, situated 

 before or, in old examples, in the middle of the length of the head. 

 Therearcfour or five longitudinal series of scales between the lateral 

 line and the ventral fin. Upper margin of the dorsal fin concave, 

 the third and fourth rays being the longest. Body, and especially 

 the tail, compressed, oblong, its depth being contained thrice and 

 two-thirds or four times in the total length (without caudal). Colo- 

 ration uniform. 



Nile. 



o, b, c, d, e, f, g. Many adult, half-grown, and young specimens. 



Lower Nile. 

 h. Fine specimen, 21 inches long. Chartoum. From Mr. Pethe- 



rick's Collection. 



