110 D. E. SAVAGE 



Plesiadapis gidleyi, among the eiglit known from the San Jose sur- 

 face and among the eleven from the pocket, is common to the two 

 assemblages. The larger animals such as Phenacodus and Periptychus 

 are known only from surface finds; so that one's concept of faunal 

 composition would be completely different if only the surface ma- 



MASON POCKET ELSEWHERE 



MULTITUBERCULATA 



PTILODONTIDAE 

 Ectypodus musculus 12+ 



MARSUPIALIA 



DIDELPHIDAE 

 Peradecfes elegans 20 



INSECTIVORA 



LEPTICTIDAE 



Leptacodon tener 2 



Xenacodon mutilatus I 



PICRODONTIDAE 

 Zanycteris paleocena I 



PRIMATES 



PLESIADAPIDAE 



Plesiadapis gidleyi 20+ I 



?APATEMYIDAE 



Labidolemur soricoides 2 



CARPOLESTIDAE 



Carpodapfes aulacodon I 



ANAPTOMORPHIDAE 



Navajovius kohlhaasae 3 



PHENACOLEMURIDAE 



Phenacolemur frugivorus 7 



CARNIVORA 



ARCTOCYONIDAE 



Chriacus sp. • • I 



Thryptacodon oust rails I 



MESONYCHIDAE 



?Dissacus sp. . . I 



CONDYLARTHRA 



PHENACODONTIDAE 



Phenacodus grangeri • • 9 



Phenacodus matthewi • • \ 



Phenacodus gidleyi • • I 



Phenacodus sp. • • I 



PERIPTYCHIDAE 

 Periptychus superstes • • 5 



TOTALS 70+ 20 



Fig. 4. Census of individuals of various land mammal species from 

 the Mason Pocket and from elsewhere in the San Jose formation, late 

 Paleocene, Colorado. Modified from Simpson (1935, p. 4). 



