SATS Bulletin American Museum of Natural History. * AVG: XXXIV, 
in some genera are very ‘loge to certain Eocene aren das On the other 
hand, the position of the mental foramen is peculiar to Insectivora (although 
not found in all of them) and the characteristic specialization of the front 
teeth is more commonly found in Insectivores than in Primates. An 
approach towards it is seen in J'etoniws. The characters of the molars are 
such as might be found in any very primitive frugivorous mammal of 
minute size, whether Insectivore or Primate. The upper teeth, skull and 
skeleton are wholly unknown. 
The Tarsiid resemblance is closest in Z'rogolemur, in which the front 
tooth is less enlarged, the position of the mental foramen further forward, 
and the premolar and molar teeth are more of Tarsiid type, nearest to 
Omomys. On the other hand Phenacolemur of the Lower Eocene differs 
widely from the Tarsiidse and has no suggestion of Primate relationship in 
the molars. It appears to be rather nearly related to Apatemys, especially 
A. bellus. A. bellulus and Uintasorex of the Bridger are intermediate be- 
tween the typical Apatemys and Trogolemur, but in form of teeth agree 
better with the latter. 
It is possible that two different phyla are here confounded, Trogolemur, 
Apatemys bellulus and Uintasorex being successive stages of a diprotodont 
specialization derived from the Tarsiide, Phenacolemur and Apatemys 
bellus derivatives for some different stock. But it appears unwise to split 
up the family until we know more about it. 
Trogolemur Matthew 1909. 
Type, T'. myodes from the Middle Eocene. 
Generic characters: Molars simple, tritubercular with large basin xealt wide and 
low-crowned, p? small internal, connate. Premolars three, short and wide crowded, 
simple, pz minute, p; small, ps moderately large with small imperfectly distinct heel. 
Anterior tooth enlarged, long-rooted, compressed, crown unknown. 
This genus is much closer to Tarsiide in the construction and propor- 
tions of premolars and molars than is any other Apatemyid. The much 
greater enlargement of the anterior tooth and the peculiar position of the 
mental foramen are the chief distinctions. From Smzlodectes, which it 
resembles less closely, it is also distinguished by the much greater reduction 
of p3 and higher specialization of the anterior teeth, broader and shorter 
molars. 
Schlosser’ has referred Trogolemur to the Anaptomorphide. The’ 
reduction of the front teeth to a single greatly enlarged pair, as in Cheiromys 
! Schlosser, 1911, in Zittel’s Grundzuge d. Pal., Vertebrata, p. 549. 
