Plate LIX 



Comparative Series: Upper and Lower Teeth of Xotharcfus and Alouatta {" Mjjcetes") 



1. Notharctus crassiis. Amer. Mas. No. 11982. Middle Eocene (Upper Bridger). Right upper premolar-molar series and canine. 



X ■?. 



2. 4ZoMa«a ("Mj/cetes") sp. Amer. Mus. No. 14660. Right upper tooth-row. X?. 



3. Notharctus crassus. Amer. Mus. No. 11982. Middle Eocene (Upper Bridger). Right ramus of mandible with teeth. X ?. 



4. Alouatta {"Mycetes") sp. Amer. Mus. No. 14660. Right ramus of mandible with teeth. X i- 



