200 LEONTOCEBUS 



Geogr. Distr. Region of the Upper Amazon. Pebas, Ecuador, 

 (Castelnau and Deville). 



Genl. Char. Similar to L. devillii, back uniform black. 



Color. Head, neck, ears, throat, chest, arms, hands and feet 

 black; legs bright reddish chestnut, hairs on rump and flanks tipped 

 with same ; abdomen and base of tail, reddish chestnut, rest of tail 

 black ; white hairs around mouth and beneath eyes. Ex type Munich 

 Museum. Skull in specimen. 



Measurements. Similar in size to L. fuscicollis ; tail, 315. Skull : 

 occipito-nasal length, 44; zygomatic width, 26; intertemporal width, 

 23 ; palatal length, 13 ; width of braincase, 27 ; median length of nasals, 

 6; length of upper molar series, 11 ; length of mandible, 26; length of 

 lower molar series, 12. Ex specimen in British Museum. 



The type of Midas rufoniger I. Geoffroy, in the Paris Museum, 

 agrees perfectly with the above description, except the upper part of 

 the throat is a yellowish brown. This appears to be caused by the 

 paucity of hair on that part, there not being enough black tips, which 

 produce the color for this part, to be spread all over. Wherever the 

 hairs are sufficiently numerous the color is black. Geoffroy's species 

 is without doubt the same as L. nigricollis (Spix). 



There are two examples of this species in the Munich Museum both 

 marked 'types.' These are in good condition, only slightly discolored 

 by dust, but the dark colors of the pelage have not faded. The skulls 

 of each are in the specimens. 



Bates (1. c.) has given a very interesting account of this monkey 

 under the name of Midas rufoniger I. Geoff. Its habits are the same 

 as those of C. ursulus and he imagined it was a form or race of the 

 same stock, modified to suit the altered local conditions under which 

 it lived. One day, he says, while walking along a forest pathway, he 

 saw one of these small creatures which was passing with a number of 

 his fellows, miss his hold and fall head first about fifty feet to the 

 ground. He managed to alight on his hands and feet, however, in 

 the path, and turning quickly around he stared at the intruder on his 

 domain for a few moments, and then bounded away to climb another 

 tree. 



Leontocebus cheysopygus (Wagner). 



Hapale chrysopyga Wagn., Schreb., Saugth. Suppl., I, 1840, p. 

 249; V, 1855, p. 138; Schleg., Mus. Pays-Bas, Simue. 1876, 

 p. 254. 

 Jacchus chrysopygus Mikan, Delect., fasc. Ill, fig. 



