160 TEN years' progress in vertebrate paleontology 



dence as it stands, is not in accord with the later distributional relations 

 of this order as the present writer sees them. What we know of the 

 modern and Pleistocene and later Tertiary distribution of different spe- 

 cies of Proboscidea seems to point to an Asiatic, not Ethiopian, center of 

 dispersal for this order since the Miocene. It is, of course, possible that 

 the Proboscidea reversed the normal course of migration and dispersal 

 and were at first Ethiopian, then Asiatic. But we have hitherto known 

 nothing of the Oligocene fauna of Asia, and until we know the results of 

 Pilgrim's and Cooper's explorations in the Oligocene of Baluchistan it 

 may be well not to regard the African origin of the Proboscidea as a 

 settled question. 



The third autochthonic group, Hyracoidea, had been known only by 

 the two closely related surviving genera, Procavia and Dendrohyrax, lim- 

 ited to Africa and S3Tia, and without known fossil relatives except the 

 Pliohyrax of the late Tertiary of Samos and Pikerni. In the Fayum 

 fauna Hyracoids are abundant, small or medium sized, some bunodont, 

 others bunolophodont. It is generally accepted that they took the place 

 in the Ethiopian early Tertiary fauna of the missing Perissodactyls and 

 Artiodactyls, as the Notoungulata did in the Tertiary of South America. 



Marine Group 



The Sirenians and Cetaceans are chiefly from the marine Mokattam 

 and Quasr-es-Sagha beds, late Eocene in age. The Sirenian genera, 

 Eotherium, Eosiren, and Protosiren, show a very marked approach in the 

 structure of skull, teeth, and certain parts of the skeleton to the early 

 Proboscideans, especially Moeritlieriuni. and leave little doubt of the deri- 

 vation of Proboscidea and Sirenia from a common early Eocene ancestor. 

 The Cetacea include besides ZeugJodon, already known from the Euro- 

 pean and North American Upper Eocene, other more primitive genera, 

 Eocetus and Protoceius, which show a marked approach toward the Creo- 

 donta and certain special points of resemblance to Hycenodon. The latter, 

 Matthew has shown, must be ascribed to convergence, and the former are 

 more probably resemblances to the common primitive Creodont-Insecti- 

 vore stock than to the Creodonts in particular. There are equally marked 

 points of resemblance to certain of the Eocene Insectivora. 



Insectivores and Primates 



Two scarce and little known genera, Metolhodotes and Ptohmaia. have 

 been provisionally referred to the Insectivora. The former is said by 



