{fRANSACTIONS OF SECTION D. 431 
and Lake Victoria. A remarkable negative feature is the absence, as in Syria, 
of Labeo, a genus abundantly represented in the Nile, Senegal, Niger, Congo, and 
Zambesi, and India, and more scantily in East and South Africa. It is a 
suggestive fact, tending to show that, somehow or other, Lake Tsana has only 
comparatively lately been in communication with the Nile, that the Varicorhinus 
and several of the Barbus are common to this lake and to some of the rivers of 
the eastern watershed ; whilst not one of the Cyprinids occurs also in the Nile. 
The main stream of the Blue Nile has only been explored up to Rosaires, but the 
fishes obtained in that part of the river do not in any way difler from those of 
the Upper Nile. 
The chief character of the rivers east of the Rift Valley is, as already stated, 
the number of species of Barbus. The Cyprinids are further represented by a 
few Labeo and Discognathus, by a Neobola, and by the only African representa- 
tive of the Indo-Malay genus Rasbora. The Mormyrids are represented by six 
species only. The few Characinids belong to the genus Alestes and to its near 
allies Micralestes and Petersius. Of the twenty Silurids, some are widely distri- 
buted species, others are common to the Nile or to the Zambesi, whilst among the 
species with a restricted habitat we note a Physatlia, two Bagrus, two Amphilius, 
a Synodontis, and two Chiloglanis—altogether a poor series as compared with other 
districts of Tropical Africa—and not a single autochtonous genus. A species of 
the remarkable genus Aneria, a tew Cyprinodontids, and a few Cichlids of the 
genus Tilapia complete what is for a district of that extent, well watered and 
within the tropics, a very meagre list. 
IV. Tue Sovrnern Svb-RuGton, 
Africa south of the Zambesi system has a “poor fresh-water fish-fauna, but 
this is easily accounted for by the intermittent character of most of its rivers. 
The list I have drawn up from available data includes only fifty species, seven of 
which are partly marine. When discussing the distribution of the South 
African fresh-water fishes eight years ago Professor Max Weber compiled a list 
of sixty-four species ; but this included a number of truly marine forms, occurring 
only in estuaries, besides a few of very doubtful determination, which I am 
obliged to leave out. The majority of the exclusively fresh-water fishes are 
Cyprinids, viz., seventeen Barbus and three Labeo. Characinids are represented 
by the widely distributed Hydrocyon lineatus, which occurs in the Limpopo, and 
the newly discovered Alestes natalensis, from near Durban. Three Clarias, an 
Eutropius, a Gephyroglanis, and a Galeichthys, the latter semi-marine, represent 
the Silurids. The two Galazias, as distinguished by Castelnau, the most remark- 
able type of the South African fish-fauna, and the two Anadas, are confined to 
the south-western district of Cape Colony. A Cyprinodontid of the genus 
Fundulus has been described from False Bay. Four Gobies and five Cichlids of 
the genera Hemichromis, Paratilapia, and Tilapia complete the list. 
Poor as it is in fishes, the south-western district—the Erica or Protea district 
of Max Weber—derives a special character from the presence of the genera 
Galavias and Anabas. The western district is also poor, and has only repre- 
sentatives of three families: Cyprinids, Silurids, and Cichlids; whilst the eastern 
district, from the Limpopo system and the tributaries of the Orange River to Natal, 
is the richest, two families, Characinids and Gobiids, being represented in addi- 
tion to the three above named. The recent discovery in the Vaal River of a 
Gephyroglanis, a Silurid genus otherwise known only from the Congo and 
Ogowe, deserves notice. 
Whether the subterranean reservoirs of the Kalahari are inhabited by fishes, 
as is the case in the Northern Sahara, is still unknown. 
Excepting such forms as are believed to have been directly derived from 
marine types, there is every reason to regard the piscine inhabitants of the fresh 
waters of South Africa as comparatively recent immigrants from the North, 
