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 tailis 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 
cne 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 
ire called “ Devil monkeys” by the Indians. They are very 
jelicate, and soon die in captivity. 
