OF WESTERN NORTH AMERICA. 103 



Range of Eocene genera — Continued. 





Basal. 



Lower. I Middle. 



Upper. 



First 

 phase. 



Second 

 phase. 



First 

 phase. 



Second 

 phase. 



First 

 phase. 



Second 

 phase. 



First 

 phase. 



Second 

 phase. 



ARTIODACTYLA. 

 A oYi cf*nr\H on I"! H trX^ 



















2 



3 

























4 



1 



X 



1 



2 

 ? 1 



1 



1 



2 

 ? 1 





2 



/-» T»/-v a n G 





















"NTq nf^mPT\7 Y 











? Stenacodon 











TTplr\h \7n G 











1 



? Tt"h m m r^H r^n 









Tl n n m T \ r Y 













OTPr^H An cip 

















Protoreodon 



4 



1 

 1 



Protagriochoerus 

















Hyomervx 

















Camelidse aut Hvpertragulidse 

















Leptotragulus 



? 



X 

 X 



3 

 1 

 1 

 1 



Leptoreodon 













Protylopus 













Oromeryx 





























LOWER OLIGOCENE. 



Chadron (White River group). 



Titanotherium zone. 



1. Chadron, South Dakota and adjoining parts of Nebraska and Wyoming. 



2. Horsetail Creek, northeastern Colorado. 



3. Pipestone Creek, Thompson Creek, and other localities in Montana. 



4. Swift Current Creek, Canada. 



MARSUPIALIA. 



DlDELPHYID^. 



Peratherium titanelix Matthew. 



CARNIVORA (CREO- 

 DONTA). 



Hy^nodontid^. 



? Pseudopterodon m i n u t u s 



(Douglass) a 



Hemipsalodon grandis Cope 



Hysenodon sp 



CARNIVORA (FISSI- 

 PEDIA). 



Canid^. 



Daphsenus dodgei Scott 



Daphsenus sp 



Cynodictis paterculus Matthew . 



Cynodictis sp 



? Cynodon sp 



MUSTELID^. 



Bunaelunis infelix Matthew . 

 Felid^. 



Dinictis fortis Adams. 

 Dinictis sp 



1. 



2. 



3. 



4. 







X 









X 











X 



X 









X 









X 





? 







\ X 





X 







X 













X 





X 









X 









INSECTIVORA. 



Leptictid.e. 



Ictops acutidens Douglass. 

 Ictops thomsoni Matthew. , 

 Ictops montanus Douglass. 

 Ictops intermedins Douglas 



Ictops tenuis Douglass 



Ictops m.ajor Douglass 



? Chrysochlorid^. 



AptemodusmediaevusMatthew. 

 Xenotherium unicimi Douglass . 



Fam. indet. 



Micropternodus boreal is Mat- 

 thew 



RODENTIA. 



SCIURID^. 



Prosciurus vetustus Matthew.. 

 Prosciurus jeflersoni Douglass. 



Castorid^. 



Cylindrodon fontis Douglass. . . 

 Eutypomys sp. i» 



1. 



2. 



3. 







X 







X 







X 







X 







X 







X 







X 







X 







X 







X 







X 







X 



X 



a The type of this species is at present indeterminate. The reference to Pseudopterodon is based on 

 the specimen figured by Matthew, 1903. 

 b Auct. L. M. Lambe in lit. 



