4 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I46 



not coincidental that such unrelated animals as Kinkajous (Potos), 

 Olingos (Bassaricyon), and Woolly Opossums (Caluromys), which 

 are also nocturnal and arboreal, have fur of similar texture. 



Two typical semierect preleaping postures. 



Night Monkeys are extremely active and agile. (Hill, 1956, says 

 that they are fairly slow moving; but this is certainly not true of 

 individuals in the wild or of healthy captive individuals in adequate 

 cages.) Like monkeys of the genera Callicehiis, Pithecia, and Cacajao, 

 they are expert and powerful leapers. Rapid movements through the 



