420 REPORT—1905. 
known to live in brackish water, whilst examples are known of their occurring 
far out at sea. Under these circumstances the wide range of the principal African 
genera—Cyprinodon, S. Europe, 8.W. Asia, N. Africa, North and South 
America, Haplochilus, Africa, 8. Asia, Japan, North and South America, and 
Fundulus, 8. Europe, Africa, North and South America—is not surprising. 
Cyprinodon is probably an immigrant from the North—where its close ally Pro- 
lebias was abundantly represented in the Oligocene and Miocene of Europe—- 
whilst Fundulus and Haplochilus may have reached Africa by the sea. 
THe OPHIOCEPHALID® AND ANABANTIDA.— Unknown fossil, and now restricted 
to Africa and South-Eastern Asia, we have no means of telling in what part of 
the world these two closely allied families originated. The Anabantide are more 
numerous in species, and these are of a more generalised type, in Africa than in 
Asia, 
Tue Nanpipa.—The recent discovery of Polycentropsis in the Lower Niger 
has added a genus to a small family previously known to be represented by three 
genera in South-Eastern Asia and by two in the northern parts of South America. 
The latter are more nearly related to the African genus than the former. Too 
little is known of the habits of these fishes to decide whether the hypothesis of 
a migration across the Atlantic, in the days when a shallow area with a string off 
islands connected the old world and the new, answers for their distribution. 
Their systematic position—specialised Perciformes—is against the assumption of 
their having existed in Cretaceous or early Eocene times, No fossil forms are 
known. 
Tus OspHromeNtD®.—The only African representative, the genus Meeracan= 
thus, with a single species in the Ogowe, is hardly separable from the genus Betta, 
which, with six other genera, is characteristic of the Indo-Malay region and China. 
Paleontology gives no information on the earlier distribution of these highly 
specialised fishes. That a type so well organised for adapting itself to all sorts of 
waters, and so ready to acclimatise itself in any part of the tropical or sub- 
tropical countries where it has been transported by man, should have so restricted 
a range seems remarkable. Were it not for the existence of this African form, 
far away from the other members of the family, one might have felt inclined to 
look wpon the Osphromenide as a very recent group, which has not had time to 
spread far from its original centre in South-Western Asia. 
Tue Cicuiipa.—As regards the number of species (179) this family ranks: 
next to the Cyprinide (202) and the Stluride (187) in the African fresh-water 
fish-fauna, and, like these, it has representatives nearly all over the great conti- 
nent. Although Cichlids may thrive in inland waters of considerable salinity, 
they are not known to have ever been found in the sea, even near the mouths of 
rivers. The facility with which they establish themselves in isolated waters, 
often untenanted by other fishes, such as wells in the Sahara, salt-water pools in 
the interior of East Africa, &c., haslong been known, but by what agency this has: 
been effected remains unexplained. Quite recently Dr. Lénnberg has reported on 
the exploration of a small isolated lake of volcanic origin on the Cameroon 
mountain, a lake 200 feet above sea-level, without any outlet, and situated about 
twelve miles from the nearest river and twice as far from the sea-shore. This: 
lake was found to have a fish-fauna consisting exclusively of Cichlids, belonging: 
to three genera and five species, two of which have been described as new. 
The great bulk of the family inhabits Africa, including Madagascar, and! 
America, from Texas to Montevideo; the number of generic types is greater, 
although the species are only slightly in excess, in the former than in the latter 
part of the world. Seven species inhabit Syria, three of these being also found in 
the Nile, and three are known from India and Ceylon. The American and Indiani 
genera are all distinct from the African, A great number of species (fifty-five), 
all but one endemic, inhabit Lake Tanganyika, of which they form a little over’ 
two-thirds of the fish-fauna; and many of these species belong to distinct genera, 
