1893.] NATURAL SCIENCES OF PHILADELPHIA. 185 



NOTES ON CHOEROPSIS LIBERIENSIS (Morton). 

 BY HENRY C. CHAPMAN, M. D. 



It is well-known that the late Dr. Samuel G. Morton, regarding cer- 

 tain peculiarities presented by the skull of the hippopotamus inhab- 

 iting the west coast of Africa as specific in character, proposed in 

 communications made to the Academy 1 that the latter should be 

 distinguished from that of the east coast as Hippopotamus minor, 

 afterward liberiensis, the former retaining the name of Hippopot- 

 amus amphibius given to it by Linnaeus.' 2 The Academy having 

 afterward acquired an entire skeleton of theLiberian hippopotamus, 

 the late Dr. Leidy took up anew the study of its osteology 

 and more especially of the skull. After a most careful com- 

 parison of the skulls of the two species, Dr. Leidy came to the 

 conclusion that the hippopotamus of Liberia differed so much 

 from that inhabiting the Nile, the Cape of Good Hope, etc., that the 

 Liberian animal should be considered as constituting, not only a dis- 

 tinct species, but a distinct genus, and proposed 3 that the new 

 genus should be named Chaerodes. Learning, however, that this 

 name had already been appropriated, having been previously given 

 to an insect, Dr. Leidy suggested that the name Chaerodes should 

 be changed to Choeropsis* While Dr. Leidy's views as to the 

 generic distinction between Hippopotamus and Choeropsis have been 

 accepted by such high authorities as Gratiolet, 5 Milne Edwards 6 and 

 Huxley 7 , by many zoologists Choeropsis is regarded as a species of 

 Hippopotamus, and by some only as a variety of Hippopotamus 



1 Proc. Acad. N. S.. 1844, Vol. 2, p. 14; Journal A. N. S., Vol. 1, 1849, p. 231. 

 2 Syst. Nat. 12 ed.. Vol. 1, p. 10, 1766. 



3 Proc. A. N. S., 1852, Vol. 6, p. 52. 



4 Journal A. N. S.. 2 Ser., Vol. 2, 1853, p. 213. 



5 Recherches sur l'anatomie de l'Hippopotame, Paris, 1867, p. £02. Gratiolet 

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

 Ditomeodon . 



6 Recherches sur les Mammiferes, Paris, 1868-1874, p. 43. 



7 Huxley, Anatomy of Vertebrated Animals, 1872, p. 319. At least, Huxley 

 says, " The Hippopotamidae are represented at present only by the genera Hippo- 

 pota?nus and Chaeropus." " Chaeropus has only two incisors in the lower jaw " 

 — by Chaeropus is, presumably, meant Choeropsis. 



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