PYGATHRIX 31 



o.* Nuchal patch pale drab gray 



tail dark gray P. carbo. 



b* Nuchal patch creamy white, 



tail huffy gray P. sanctorum. 



b." No nuchal patch P. nubigena. 



b.' Thighs white extending to body. 



a." Legs below knees grayish white P. dUecta. 



b." Legs below knees black. 



a.^ Forearms black P. natuncs. 



b.^ Forearms not black. 



a.* Nuchal crest broccoli brown. 



a.^ No white on chest P. rhionis. 



b.^ With white on chest P. cana. 



fc.* Nuchal crest grayish brown. .P. siamensis. 



c! Thighs white not extending to body P. catemana. 



j. General color gray. 



a.' Hands and feet white. 



a." No white on head P. aygula. 



b." With white on head P. fuscomurina. 



b.' Hands and feet black. 



a." No white on head P. sabana. 



b." With white on head 



a.^ Black stripe from eye to ear P. everetti. 



6.3 No black stripe from eye to ear P. hosei. 



c." White spot on forehead rest of head 



black P. thomasi. 



k. General color black. 



a.' Sides of head white. 



a." Under parts of body rufous P. potenziani. 



b." Under parts of body black P. franqoisi. 



b.' Sides of head yellowish white. 



a." Inner side of thighs white P. cephaloloptera. 



b." Inner side of thighs not white ... .P. c. monticola. 

 c' Sides of head yellow tinged with red. 



a." Tail jet black P. johni. 



b." Tail at base gray P. ursina. 



I. Entire pelage black P. aurata. 



m. General color speckled white and black. 

 a.' Tooth rows curved. 



a." Much silver in the black P. cristatus. 



b." Less silver in the black P. c. pullata. 



