2 SJOSTEDTS KILIMANDJARO-MERU EXPEDITION. 5. 



described from Lake Victoria. The fishes of the Kilimandjaro-Meru district are pro- 

 bably not all known yet. From the notes above it will appear, that hitherto about 18 

 species of fish have been recorded, and of them not less than 9 belong to the genus Bar- 

 bus, which has produced a very great quantity of different forms in Africa. It is highly 

 probable that many of these are restricted to a very limited area of distribution and 

 that a great number ought to be regarded rather as local races or geographic subspecies, 

 than as real species. This is, however, a very difficult question, and the problem cannot 

 be satisfactorily solved before a rich material from different waters and representing 

 different sizes and ages has been collected. Until this has been done it only remains to 

 describe and report upon the additions of material which has been obtained. 



The fish fauna of Usambara appears to be rather unexplored as yet. Of the five 

 species collected there by Professor SJOSTEDT only one Barbus jacksoni from Mombo 

 represented a species which was known before (from Kilimandjaro and the Wembere 

 steppe). Three species are new and described below, the fifth would probably have 

 proved to be new as well, if the material had admitted a satisfactory determination. 



Fam. (liaraciniclap. 



Pctersiiis tangensis n. sp. 

 18 specimens collected in a pool on inundated ground at Tanga, June 1905. 



Depth of body about four times in total length without caudal, length of head 

 4V* (in small specimens hardly 4 times). Mouth oblique lower jaw, however, hardly 

 extending beyond snout. Diameter of eye 2 3 /4 in length of head (in small specimens 

 2V2). Interorbital space about equal to 8 /4 diameter of eye. Snout shorter than eye. 

 Dorsal fin with 10 rays 8 of which are branched. Its height almost equal to the length 

 of head. Its origin is situated in about equal distance from anterior border of eye and 

 middle of the root of caudal. Adipose fin small and slender its height hardly equal to 

 3 /4 the diameter of eye. Its distance from the rayed dorsal about 2Va times the length 

 of the base of the latter. Anal with 19 rays 17 of which are branched. Pectoral not 

 quite as long as head, and not quite reaching the base of the ventrals, which just reach 

 the vent. Caudal deeply forked, outer rays twice as long as middle rays. Caudal pe- 

 duncle about IVa times as long as high. Lateral line with 36 scales. 6'/2 scales be- 

 tween lateral line and origin of dorsal 2 l /n between lateral line and base of ventral. 



Silvery, probably with the back light olivaceous or greenish in life. A darker 

 silvery band along the side above the lateral line separates the less shiny lower parts 

 from the olivaceous back. Total length with caudal in the longest specimen 57 mm. 



The only other species of Petersius from East Africa P. conserialis is easily distin- 

 guished from this one by it smaller eye (3Va times in length of head), longer anal (21 

 rays) smaller number of scales in the lateral line (33), greater height of body (only 2 2 /s 

 times in total length) etc. 



In general appearance P. tangensis may be most similar to P. modestus BOTJLEN- 

 GER from Congo, Lake Leopold, but the former has a longer caudal peduncle. The lat- 



