482 Miscellaneoufi. 



the hippopotamus of Liberia differed so much from that iuhabitinof 

 the Nile, the Cape of Good Hope, &c., that the Liberian animal 

 shouhl be considered as constituting not only a distinct species, but 

 a distinct genus, and proposed * that the new genus should be 

 named Clwrodcs. Learning, however, that this name had already 

 been ap])ropi'iatcd, having been previously given to an insect, 

 Dr. Leidy suggested that the name Clwrodes should be changed to 

 CJioeroj^slsf. While Dr. Leidy's views as to the generic distinction 

 between Hippopotaimis and Chceropsis have been accepted by such 

 high authorities as GratioletJ, Milne-Edwards §, and Huxley ||, 

 by many zoologists Chosrojisis is regarded as a species of Hippopo- 

 lamus, and by some only as a variety of Hippopotamus amplubius % . 

 Thus, for example, Flower **, a very high authority, does not 

 consider the difference in the shape of the cranium and in the 

 number of the incisor teeth in the lower jaw as warranting the 

 establishment of the genus Chce/ropsis. The difference presented by 

 the crania in the two kinds of hippopotamus Flower regards as 

 similar to those " between the tiger and the smaller species of FcUs, 

 the gorilla and baboons and the smaller allied apes." In the judg- 

 ment of the author, however, it may be at least questioned whether 

 the differences existing between the smaller species of FcUs do not 

 justify separating them into distinct genera. On the other hand, 

 although the gorilla has descended in all probabilitj' from some 

 baboon-like foim, zoologists do not as yet recognize these two apes 

 as species of the same genus. The fact that Hippopotamus amphi- 

 Imis, syn. Tetraprotodon, has, according to Gaudry ft, exhibited in 

 one instance unilateral hexaprotodoutism, and Chceropsis, according 

 to Flower %%, in one instance unilateral tetraprotodontism, would 

 influence but few palaeontologists in regarding, like Lydekker §§, 

 Hexaprotodon, I'draprotodon, and Chceropsis as merely species of 

 one genus, Hi2>2^02)otamns. Hexaprotodon and Tetraprotodon, with 

 the incisor formula 3 — ^ aud g— ^ respectively, are still considered 

 either as subgenera, as they were originally by Falconer and 



* Proc. A. N. S. 1852, vol. vi. p. 52. 



t Journ. A. N. S. ser. 2, vol. ii. 1853, p. 213. 



X ' Recherches svu- ranatomie de I'llippopotame,' Paris, 1867, p. 202. 

 Gratiolet, apparently ignorant of Leidy's description, named the Liberian 

 bippopotamus Ditomeodon. 



§ ' Recherches sur les Mammiferes/ Paris, 1868-1874, p. 43. 



II Huxley, ' Anatomy of Vertebrated Animals,' 1872, p. 319. At 

 least, Huxley says, " The Hippopotamidaj are represented at present only 

 by the genera Hippopotamus and Charopus." " Chan-opus has only two 

 incisors in the lower jaw "■ — by Cheer opiis is, presumably, meant 

 Cha^ropsis. 



^ Carus, ' Zoologie,' 1868, p. 145. 



■** Proc. Zool. Soc. London, 1887, p. 612. 



tt Ball. Soc. Geologique, ser. 3, vol. iv. p. 504. 



\X Op. cit. 

 ^ §§ 'Memoirs of the Geological Survey of India,' 1884-1886, vol. iii. 

 p. 47. 



