406 Prof. K. A. von Zittel—On the Mammalia. 
PERISSODACTYLA. 
EUROPE. NorTH AMERICA. 
Hyracotherium. Hyracotherium. 
Pachynolophus. Pachynolophus. 
Lophiodon. Lohippus. 
Brachydiastematotherium. feptodon. 
Sypstenodon. 
Lambdotherium. 
ARTIODACTYLA. 
Lophiodocherus. fantolestes. 
Protodichobune. 
AMBLYPODA, 
Coryphodon. Coryphodon. 
Manteodon. 
Lictacodon. 
TILLODONTIA. 
Lsthonyx. Esthonyx. 
(Platycherops.) Calamodon. 
+ Calamodon. Stylinodon. 
Dryptodon. 
? Ectoganus. 
RopEntTIA. 
Decticadapis. Paramys. 
INSECTIVORA. 
Adapisoriculus. Diacodon. 
Centetodon. 
CREODONTIA. 
Paleonictis. Palzonictis. 
{Proviverra. Oxyeena. 
\ Cynohyenodon. | Amblyctonus. 
+Arluravus. Pachyena, 
? Argillotherium. Anacodon. 
Sinopa. 
Didelphodus. 
Dissacus. 
Miacis. 
Didymictis. 
Prosimim (PACHYLEMURIDZ). 
1 Pelycodus. Pelycodus. 
; Hyopsodus. Hyopsodus. 
Lemuravus. 
Microsyops. 
Tomitherium. 
Anaptomorphus. 
Mixodectes. 
Cynodontomys. 
? Sarcolemur. 
? Apheliscus. 
? Opisthotomus. 
If we compare with each other the Mammalian faunas living in 
the Older Tertiary period in these widely separated regions, we are 
at once struck by the contrast of the poverty in genera and species 
of the Huropean region with the abundance in the American 
localities. If we consider, however, that the few areas in Hurope 
yielding the materials of this fauna are of very limited extent in 
Northern France, England and Switzerland, whilst in Wyoming, 
