5 
regions ; seventeen out of the twenty-six families or groups 
found in the former are represented by one or more species 
in Africa, and many of the African species are not even 
generically different from the Indian,” and as the majority 
of these groups have many more representatives in India 
‘than in Africa, it has been assumed “that the African 
species have been derived from the Indian” stock, but 
even to such an assumption there are exceptions. 
The African fresh-water region comprises, according to 
Dr. Giinther’s arrangement, the whole of the African con- 
tinent south of the Atlas and the Sahara, but for the 
purpose of this Paper, in which I treat of the marine fauna 
as well, I would dwell generally on the western coast line 
of that Continent lying between 30° N. lat. and 35°S. lat, . 
for within such latitudes lie not only the coast line and 
adjacent waters, but also the Canaries, Cape Verde Islands, 
Fernando Po, Princes Island, St. Thomas and Annobon, to 
which I would like to make a brief reference. 
I am, apart from interest, the more induced to so act as 
“the difference between the tropical and southern parts of 
Africa consists simply in the gradual disappearance of 
specifically tropical forms, whilst Sz/uroids, Cyprinoids, and 
even Labyrinthici,” which are peculiar to the warmer lati- 
tudes “penetrate to its southern coast”; thus “no new 
form entering to impart to South Africa a character dis- 
tinct from the central portion of its Continent.” 
Whilst deciding not to encompass in this Paper widely 
spread comparisons even as far as the African region goes, 
extending in the north-east as to its fauna by the Isthmus 
of Suez into Syria, “the system of the Jordan presenting 
so many African types that it has to be included in a 
description of the African region, as well as of the Europo- 
Asiatic,” I may say that two hundred and fifty-five species 
