256 EOCENE FAUN^. 



justified by the flat tibio-tarsal articulation. They were furnished with a 

 long and large tail. Probably some of the species resembled in propor- 

 tions the Mystomys and Solenodon, now existing in Africa and the West 

 Indies, but they mostly attained a much larger size. The habits of many 

 of them were probably aquatic. 



Classification. To the Creodonta I have refeired,* on the information 

 which we possess, the genus Arctocyon of Blainville. Professor Gervais 

 has discovered that it possessed the very small cerebral hemispheres charac- 

 teristic of the Creodonta The olfactory lobes are large, and project far 

 beyond the hemispheres, while not only the cerebellum, but probably the 

 corpora quadrigemina, were exposed behind. The tarsal articulation and 

 the posterior part of the mandibular bones are unknown; hence this refer- 

 ence is not certain. Professor Gervaisf regai-ds it, after Laiu-illard,t as a 

 marsupial, and establishes an especial family of the order for its reception. 

 It is, however, more probable that its affinities are with the contemporary 

 genera of flesh-eaters, Palceonyctis Blv., and Pterodon Blv., genera w'hich 

 have near allies among the American forms. Palceonyctis was the contem- 

 porary of the Coryphodons in the Suessonian period of Western Europe, 

 and presents a strong resemblance to Amhlyctonus in its mandible, the only 

 part of the skeleton known. The posterior part of the ramus is not inflected 

 according to Gervais, and he therefore does not refer it to the Marsupial ia.§ 

 The neai-est European representative of Oxyoena is Pterodon, in which the 

 form of the mandible also forbids a reference to the Marsiipialia, as Gervais 

 has remarked. Both genera are doubtless members of the suborder of 

 Creodonta. The genus Hycenodon, on the other hand, is not referable to the 

 same group, for I find in a si)ecimen of the H. requieni fi'om Dcsbruges, 

 preserved in the Museum of the Jardin des Plantes, that the scaphoid and 

 lunar bones are coossified. Moreover the figure given by Professor Gervais, || 

 representing the brain of the originally-described type, H. Icptorhynchus of 

 the Miocene period, displays characters of the true Carnivora. The anterior 

 part of the cranial cavity of the specimen molded, is broken away. 



' Report Capt. G. M. Wheelc-r'B Expl. Sun-. W. 100 Mcr., 1877, iv, pi. ii, p. 38. 

 tNouv. archives du museum, 1870,p. 150. 

 (Diet. aniv. d'hist. naturello, ix, p. 400. 

 f Nouv. archives du mnaeum, 1870, ICil. 

 I Loo. cit., pi. vi, fig. &. 



