214 



Wortman — Studies of Eocene Mammalia. 



canal is external to the orbit; (11) although not positively 

 known, the relations of the lachrymal and malar are the same. 

 There are some differences to be noted, but they relate 

 entirely to the assumption of modernized features on the part 

 of Tarsius. Upon the whole, the resemblances are so striking 

 and strongly marked that apparently there can not be the 

 slightest question, not only of the close relationship between the 

 two forms, but of the further important fact of their common 

 origin. I have already suggested that the place of this origin 

 was within an ancient circumpolar land. 



147 



148 



Figure 147. — Eight lower jaw of Necrolemur Edwardsi Filhol ; enlarged 

 several times. (After Filhol.) 



Figure 148.— Three lower molars of Necrolemur Edwardsi Filhol ; crown 

 view ; enlarged. (After Filhol.) 



Necrolemur may or may not belong in this series. If it does, 

 it is by no means as closely allied to Tarsius as the American 

 species. It has been suggested by Leche that it is related to 

 the Indrisine lemurs, and there is indeed much in favor of such 

 a view. If one compares the lower jaw of Necrolemur 

 Edwardsi, figure 147, with that of P 'ropithecus diadema, the 

 resemblance in general form is at once apparent. The loss of 

 the vestigial second tooth in Necroleinur would give the for- 

 mula of the Indrisinge, which is seven teeth in the lower jaw. 

 Necrolemur differs from Tarsius, moreover, in the more 

 advanced condition of the molars. In the lower jaw the 

 anterior cusp of the trigon, figure 148, has completely disap- 

 peared, and in the upper jaw the molars are almost fully 

 quadritubercular. Microchwrus in all probability comes in 

 the same group, and when more fully known should furnish a 

 closer approximation to the Indrisinse than Necrolemur, on 

 account of the development of a mesostyle in the upper molars. 

 A further character in which Necrolemur resembles the Indri- 

 singe is the lack of differentiation of the anterior teeth into 

 incisors and canines, as well as their tendency to the procum- 

 bent position. 



Paleontological Laboratory, Yale University Museum, 

 New Haven, Conn. 



