84 



GREGORY: NOTHARCTUS, AN AMERICAN EOCENE PRIMATE 



out behind the sacrum. The iha of the Old World monkeys diverge slightly in front, but are wider on 

 the ventral surface. In the top view, likewise, the ilia of Notharctus diverge anteriorly, while those of 

 the Cebidse and Hapalids" are more parallel to the backbone. (Plate XXXII.) 



2. The ventral border of the ilium in the lemurs, in side view, is deeply concave, while in Cebidse, 

 Hapalidffi and Old World monkeys it is nearly straight. (Plate XXXIII; Fig. 13.) 



5 



Fig. 12. romparative figures of the pelvis of Notharrliis and Lcii/iir. Natural size. 



1. Notharcius osborni. Amer. Mus. No. 11474. Ventral aspect. 



2. Lemur mongoz. Amer. Mus. No. 22886. Ventral aspect. 



3. Notharctus osborni. Amer. Mus. No. 11474. Left side, with sacrum. 



4. Lemur mongoz. Amer. Mus. No. 22886. Left side. 



5. Notharctus osborni. Amer. Mus. No. 11474. Right ilium and ischium, medial aspect, showing articular surface of the sacrum. 



