On the African Species of the Genus Labeo. 300 
XXXIV.—List of the African Species of the Cyprinid Genus 
Labeo, with a Key to their Identification. By G. A. Bou- 
LENGER, F'.R.S. 
OnLy 8 species of Labeo from Africa, including 2 referred 
to Abrostomus, were regarded as valid in the seventh volume 
of the British Museum Catalogue of Fishes, published in 
1868. 30 species, 15 of which have been described within 
the last five years, appear in the following list. 
As always happens when a large number of specimens are 
available for examination, the range of variation of species 
is found to extend considerably beyond the limits assigned 
by the original describers, and, in consequence, the distinction 
of allied forms becomes a more and more difficult task. 
On the other hand, the employment of characters previously 
neglected or altogether overlooked affords a basis for a com- 
plete rearrangement, and may necessitate the breaking up of 
some of the old species. ‘The result of such a rearrangement 
is offered in the following synopsis, which is greatly needed 
owing to the state of confusion into which the distinction of 
species in this genus had gradually lapsed. 
Some of the characters used in the following key are not 
applicable to very young specimens—one to tivo inches in 
length ; such are, the position and size of the eyes and the 
shape of the dorsal fin, as all very young specimens agree in 
having the eyes comparatively large and perfectly lateral 
and the dorsal fin straight-edged or very feebly concave. 
The condition of the lips is also difficult of appreciation in 
very young specimens, owing to the small size. The num- 
bers of fin-rays and of scales are always reliable, whatever 
the age of the specimen. All African Labeo have five 
branched rays in the anal fin. The scale-formule as given 
in the key refer first to the number of scales in the lateral 
line, secondly to the numbers in a transverse series above 
and below the lateral line, in front of the origin of the dorsal 
fin, thirdly to the number of series between the lateral line 
and the base of the ventral, and lastly tothe number round 
the caudal peduncle. 
I. Barbels absent, or one on each side, often very small and hidden 
under the folds of the mouth. 
A. Inner surface of lips not bearing transverse plice ; eyes perfectly 
lateral, visible from above and from below; snout hardly as long 
as, or shorter than, postocular part of head; a small barbel; dorsal 
fin nearer occiput than root of caudal. 
1. Upper lip bordered with rounded or subconical papilla. 
Dorsal with 14-17 branched rays; Sq. 41-45 
oo, 5-6, 18-22; upper edge of dorsal fin 
23% 
