Dr. R. Woodward — Recent and Fossil Hippopotami. 117 



of one or two river- valleys, but it would hardly extend to the 

 Hippopotami spread over the broad area of England. In balancing 

 these various considerations, it seems to me most probable that the 

 Hippopotamus major was a permanent resident in the country during 

 the Pliocene period. This would involve a comparatively warm 

 temperature throughout the year as late as the deposition of the 

 ' Grays Thurrock ' beds, and the same would seem to be indicated 

 by the presence of some southern freshwater shells, 1 which are now 

 extinct in England." 3 



The living Hippopotamus amphibius appears to be met with on all 

 the tributaries of the Nile, and was in earlier times abundant in 

 Egypt also. It is still found on the Senegal and the Zambesi, and 

 along the course of most of the rivers of the eastern coast, and 

 along the coast itself, at many spots south of the equator to near 

 Natal. 



There is a second living species of Hippopotamus (H. Liberiensis) , 

 which is a much smaller animal than the common Hippopotamus. It 

 rarely attains a weight exceeding four hundred pounds, or a quarter 

 of a ton, as distinguished from the four tons weight attained by the 

 male (Obaysch) which died at the Zoological Gardens in 1878, then 

 twenty-nine years of age. One of the most important differences 

 between the two consists in the fact that the Liberian Hippopotamus 

 possesses only two incisors in the lower jaw. 



The Siwalik Hills of India, whose older Pliocene deposits are so 

 rich in the remains of Proboscidea and other Ungulata, have also 

 yielded three species of Hippopotami, namely, H. sivalensis, F. and C; 

 S. Iravaticus, F. and C. ; JH. namadicus, F. and C, and one from 

 the Narbadas, H~. palceindicus, F. and C 



The first of these, H. sivalensis, is figured in our Plate (Plate III. 

 Eig. 3-5) ; it is somewhat smaller than the existing species, H~. 

 amphibius, and has six incisor teeth in each jaw. This led Falconer 

 to propose for those Indian forms with six incisors a new generic 

 division, Hexaprotodon, the others being Tetraprotodont. H. paloB- 

 indicus and H. namadicus evidently offer in the gradual diminution 

 and squeezing out of one pair of their incisors, a distinct passage 

 from the hexaprotodont to the tetraprodont type of the modern 

 S. amphibius. 



Prof. A. Gaudry has described a Pleistocene (?) species, H~. Hippo- 

 nensis, from Algeria. A small species of Hippopotamus has also been 

 found fossil in Madagascar (Dawkins). 



But perhaps the most interesting species met with in a fossil 

 state are the Hippopotamus Pentlandi, H. von Meyer, and the 

 H. minulus of de Blainville. The latter is from the Pleistocene 

 Caves and fissures of the Island of Malta, where it has been 

 found associated with the remains of the pigmy Elephant ; 

 the former was obtained from the Grotta di Maccagnone, near 



1 Cyrena fluminalis is common in the Brickearths of the Thames Valley in associa- 

 tion with Rhinoceros Elephas and Hippopotamus. Now it is found living in the 

 Nile, and in India and China. 



2 " Falconer's Palueontological Memoirs," vol. ii. pp. 207-208. 



