770 



Comparative Morphology of Chordates 



Suborder TARSIOIDEA. Size about that of a small squirrel; 

 arboreal and nocturnal; resemble lemurs. Long hindlegs; very long 

 tail with a brush of long hair at its end. Eyes disproportionately large, 

 round, and directed forward; brain better developed than in lemurs. 



The group includes only one living genus, Tarsius, living in the 

 East Indies and Philippines (Fig. 586). 



The Lemuroidea and Tarsioidea are sometimes combined in a 

 Suborder called Prosimii. 



Suborder ANTHROPOIDEA. Mostly larger than lemurs. Eyes 

 directed forward; brain relatively large and with a much convoluted 

 cerebral cortex. Usually flat nails on all digits; the pollex and, in many 

 cases, the hallux may be opposed to the other digits. Uterus simplex; 

 one pair of pectoral mammary organs. 



Two distinct divisions are recognized: 



PLATYRHINA. Nasal septum broad and nostrils directed more or 

 less laterally. Flat nails on all digits except in marmosets (Hapalidae), 

 which have claws on all digits except the hallux. Tail long and com- 

 monly prehensile. (Figs. 587, 588). 



The two Families, Hapalidae (marmosets) and Cebidae (mon- 

 keys), occur only in Central and South America. 



Fig. 589. Baboon. (Courtesy, Museum of Comparative Zoology. Harvard Univi 



sit V.I 



