ON AFRICAN SNAKES. 193 16. A List of the Snakes of the Belgian and Portuguese Congo, Northern Rhodesia, and Angola. By G. A. Boulenger, F.R.S., F.Z.S.* [Received March 3, 1915 : Read April 13, 1915.] (Text-figures 1 and 2.) Index. Systematic : — Page Ophidia. List of the genera and species known from the Belgian and Portuguese Congo, N. Rhodesia, and Angola, with keys to their identification 193 Prosi/mna angolensis, sp. n. Angola 208 Calamelaps mellandi, sp. n. Lake Bangwelu 214 Some years ago I drew up a list of the Reptiles of Africa south of Angola and the Zambesi f , accompanied by keys to the identification of the genera and species. These keys have proved very useful, and I have been urged to prepare similar means of easy identification for the Reptiles, especially the Snakes, of other parts of Africa. Having recently bad to name large series of Reptiles from the Belgian Congo, in which work I have been helped by my excellent attendant Mr. F. Kingsbury, it has occurred to me to use the occasion for making a complete list of the Snakes hitherto recorded from that large Colony and, in order to connect this list with the one alluded to above, to include also Angola, the Portuguese Congo, and Northern Rhodesia. On other occasions I hope to compile similar lists of the Snakes of Madagascar, of East Africa north of the Zambesi, of West Africa north of the Congo, and of North Africa, so as to embrace the whole Snake-fauna of this part of the world. In the preparation of the present list I have been assisted not only by Mr. Kingsbury, but also by my young friend M. Gaston de Witte, both of whom have made many suggestions for the improvement of the keys and who have been of great service to me in testing them on unnamed material. The name of each species is accompanied by a reference to the original description, to the Catalogue of Snakes in the British Museum (1893-1896), and to Barboza du Bocage's ' Herpetologie d Angola et du Congo' (1895). Only such synonyms are added as have not been already mentioned in the Catalogue, to which the student is referred for the confirmation of the determination reached by means of the keys to the genera and species. These keys are of the most artificial kind, and apply only to the Snakes known to inhabit the region embraced in this list. The most trivial characters are often selected, in order to ensure the identification of the genus and species with the least possible recourse to an examination of the dentition, which presents * Published by permission of the Trustees of the British Museum, t Ann. S. Afr. Mus. v. 1910, p. 455.