418 ORDERS OF MAMMALIA. 



referable to the Lcmuridce, the former presenting resemblances 

 to the living Galago. 



In the Tertiary rocks of jSTorth America the researches of 

 Professor Marsh have brought to light a most interesting 

 series of Lemuroid remains of Eocene age, indicating the 

 existence during the early Tertiary period of a group of 

 forms apparently higher than the existing Lcmuridce, but 

 certainly inferior to the Catarhine Monkeys, and exhibiting 

 many generalised characters in their dentition and osteology. 

 The forms in question are divided by Marsh into the two 

 families of the Lemuravidce and Limnotheridm, represented 

 in the lowest Eocene deposits of New Mexico by the type- 

 genera Lcmuravus and Lwinotlicrium. The former of these, 

 according to its discoverer, " appears to have been most 

 nearly allied to the Lemurs, and is the most generalised 

 form of the Primates yet discovered." The brain is nearly 

 smooth and of moderate size, and the conformation of the 

 skeleton is Lemuroid. The most remarkable point about 

 Lemuravus, however, is the dentition, there being the com- 

 plete series of forty -four teeth present, and the dental 

 formula beino- — 



The genus Hyopsodus appears to be nearly related to 

 Lcmuravus. 



The genus Limnotherium — the type of the Limnotheridce 

 — is also " nearly related to the Lemurs, but shows some 

 affinities to the South American Marmosets." There were 

 only forty teeth, the dental formula being — 



2—2 1—1 4—4 3—3 



2—2 1—1^ 4—4 3 



= 40. 



" The brain was nearly smooth, and the cerebellum large, 

 and placed mainly behind the cerebrum. The orbits are 

 open behind, and the lachrymal foramen is outside the 

 orbit" (Marsh). Various other genera from the Eocene 

 rocks {Thinolestcs, Tclmatolestes, Microsyojjs, &c.) are placed by 

 Marsh in the family of the Limnotheridce. In the Miocene 



