THE DOUROUCOLIS. 167 



ears are very short, scarcely appearing above the hair of the 

 head ; the eyes are enormous and yellowish in colour, im- 

 parting to them the staring expression of nocturnal animals of 

 prey. Their tail is bushy, moderately long and non-prehensile ; 

 and the nostrils are separated by a narrower partition than in 

 the other genera of the sub-family. Their physiognomy reminds 

 one of an Owl or Tiger-cat (Bates). They are covered with 

 close, soft, woolly fur. 



In the skull the orbits are enormously large and closely 

 approximated, but yet separated by a complete bony wall ; 

 the nostrils, on the other hand, though separated in the living 

 animal by a wide, fleshy partition, have only a thin plate of 

 bone between them. The upper incisors are broad ; the 

 canines long ; and the lower incisors project forwards, some- 

 what as in the Lemurs. The arm-bone has a perforation (the 

 ent-epicondylar foramen) on its inner side above the arti- 

 culation of the elbow joint, to give passage and protection 

 to an important artery and nerve. The thumb is very short ; 

 the claws are small and weak. The dorsal and lumbar 

 vertebrae together number twenty-two, the greatest number 

 possessed by any American monkey. As in Chrysothrix, the 

 external surface of the cerebral hemispheres is smooth and 

 almost devoid of convolutions, but their inner faces exhibit 

 several of the more important grooves seen in the higher Apes. 



All the species are arboreal and nocturnal, hiding away in 

 the daytime and roaming during the night, giving vent to 

 loud howls, or Cat-like cries, as they move in quest of the 

 insects, small birds, and fruits, which form their food. They 

 range from Nicaragua to the Amazon and Eastern Peru, and 

 are called " Devil monkeys " by the Indians. They are very 

 delicate, and soon die in captivity. 



