53 



IV. CEBIDAE. 



SUB-FAMILIES. 



I. Cerebrum with posterior lobe abbreviated, scarcely covering the cerebel- 

 lum behind. Hyoid bone and thyroid cartilage greatly developed : hyoid 

 bone expanded into a sub-globular drum, with thin osseous walls, the 

 larger cornua projecting backwards, the lesser obsolete. Incisors vertical. 



MYCETINAE. (A.) 



II. Cerebrum with posterior lobe enlarged, extending backwards much 

 beyond the cerebellum. Hyoid bone and thyroid cartilage moderate. 



A. Incisors vertical. 



1. Cerebrum with convolutions well marked. Tail more or less pre- 

 hensile. 



CEBINAE. (B.) 



2. Cerebrum with convolutions obsolete. Tail not prehensile. 



NYCTIPITHECINAE. (C.) 



B. Incisors inclined forwards. Tail more or less abbreviated and bushy. 



PITHECIINAE. (D.> 



A. MYCETINAE. 



Aluatta Lac.=J/ycetes 111. 



B. CEBINAE. 

 . 1. 



Celus Erxl. 



.2. 



Sctpajou Lac. = Ateles Geoff. 

 Eriode* I. Geoff. =Brachyteles Gray. 

 Lagothrix Geoff. 



C. NYCTIPITHECINAE. 

 . I- 



Nyctipithecus Spix=Aotus (Humb) 111. (Inapplicable.) 



. 2. 



Callithrix Geoff. 

 Saimiris Geoff., Gerv. Chrysothrix Wagn. 



D. PITHECIINAE. 



Pithecia Desm. 



Chiropotes 111., Gray. 



Brachyurus $p\s.= 0uakaria Gray. 



Extinct Cebidce. 

 Protopithecus Lund. 



