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Show 1 9 0 5 .] BATRACHIANS AND REPTILES. 2 4 9 In the present uncertainty as to the distinction of species in this genus, the distribution of X. Icevis is difficult to trace. This species appears to be found all over South Africa where there is water, and it extends as far north as Angola to the West and Abyssinia to the East, the British Museum possessing specimens, which I cannot separate from the typical form, from Lake Mweru, Uganda, and Senafe. Angola specimens (X. petersii Bocage), which have been referred either to X. Icevis or to X. muelleri by Gunther, by Peters, and by myself, cannot be separated, by any character that I can detect, from X. Icevis. I have examined eight specimens, one from Benguella, received from Prof. Barboza du Bocage himself, five from Pongo Andongo, obtained by Dr. Ansorge, and two from Dr. Welwitscli's Angola collection. Bocage gives the length of the Angola specimens as not exceeding 65 millim. from snout to vent, but one of Welwitsch's specimens measures 80. In the typical X. Icevis from South Africa the subocular tentacle measures less than one-third the diameter of the eye, and is sometimes reduced to a mere tubercle, the inner metatarsal tubercle is very blunt and feebly prominent, never conical, and vomerine teeth are constantly absent. The true X. muelleri, as described and figured by Peters in his ‘ Beise nach Mossambique,' vol. iii. (1882), has the tentacle more than half as long as the eye, the metatarsal tubercle more prominent, more conical than in X. Icevis, and vomerine teeth, first noticed by Tornier, are often present. In addition to Mozambique, whence it was first described, this species is found in Nyasaland and on Zanzibar and the opposite coast. To distinguish between X. muelleri and X. Icevis is, however, not so easy as one might at first think, for the British Museum has received from Mr. C. S. Betton three specimens from hot springs near Lake Nakuro, British East Africa, which agree with the former in the prominent, conical metatarsal tubercle, and with the latter in the short tentacle and the absence of vomerine teeth. . X. clivii described from Erythrsea by Peracca, and obtained in numerous examples at Addis Ababa and Ashoofi, Abyssinia, by Mr. E. Degen, agrees with X Icevis in the proportions, in the short tentacle, and in the absence of vomerine teeth, but is easily distinguished by the inner metatarsal tubercle being armed with a black claw, as in X. calcaratas, which inhabits Liberia, Lagos, Nigeria, Cameroon, the Gaboon, and the Congo. In the males of X clivii the brown nuptial asperities, instead of being restricted to the inner side of the fore limbs, as in X. Icevis, extend as a large patch on each side of the breast. Two specimens from " West Africa," collected by Mr. Fraser, therefore probably from Nigeria or Fernando Po, which have been referred by Dr. Gunther and by myself to X. muelleri in the British Museum Catalogue, agree with that species in the size of the eye, the length of the tentacle, and the presence of vomerine |
