478 Mr. G. A. Boulenger on 



thought of sufficient importance to found a new genus (Cata- 

 stacus) on. Moreover, Bell, in his description of the genus 

 Calocaris, says that the second antenna? have u a large trian- 

 gular scale reaching to the end of the first joint," and gives a 

 figure of it at the head of his description of the only species. 

 The length of this scaphocerite seems to be only a matter of 

 degree; it is very short in the species which has just been 

 described, it is longer in Galastacus investigator is, And., and 

 Galastacus felix, and longest of all in Galastacus stiIirostris f 

 Faxon. 



C. Alcocki is easily distinguishable from C. Macandreoz by 

 the general naked appearance of the body and legs and by 

 the marked differences in the rostrum and chelipeds. 



From Galastacus stilirostris by the short external spine 

 and scaphocerite on the second antenna?, the rostrum being 

 grooved, the gastric area being smooth, and by differences in 

 the chelipeds and the telson. 



From G. investigator is and C. felix by the carapace having 

 no hairs and not being granular, in having shorter spines on 

 the second antenna?, no denticle at the end of the carina, and 

 the abdominal terga smooth, and by differences in the rostrum, 

 telson, and chelipeds. 



The species will be illustrated in an early issue of the 

 " Illustrations of the Zoology of the R.I. M.S. ' Investigator.' " 



LXIV. — Diagnoses of new Fishes discovered by Mr. J. E. S. 

 Moore in Lake Tanganyika. By G. A. BoULENGER, 

 F.K.S. 



I. Cyprinidae, Siluridae. 



Capoeta tanganicm. 

 D. 12. A. 8. L. lat. 68-70. L. tr. g=^. 



14 — lo 



Depth of body 3f to 4 times in total length, length of head 

 5. Diameter of eye 3^ in length of head, 2 in interorbital 

 width ; a very small barbel. Third ray of dorsal very strong, 

 ossified. Caudal peduncle twice as long as deep. Olive 

 above, each scale darker at the base, silvery white beneath. 



Total length 320 millim. 



North end of Lake Tanganyika. 



