LAGOTHRIX 59 



Two specimens are in the British Museum Ccllection, which ditter 

 so markedly from all others, that it seems impossible to assign them to 

 any known or described species. The fur is soft and very thick par- 

 ticularly so at the base of the tail. One is dark purplish brown or 

 black on the upper parts to rump, when it becomes blackish gray on 

 legs and tail ; the other example is darker, being nearly black with but 

 little of the purplish shade. The skulls resemble, as may be expected 

 those of L. LAGOTRiCHA and L. infumata, in general, but the nasals 

 have a depression in the center, and the anterior half stands at right 

 angles to the posterior, and they are very broad anteriorly ; the brain- 

 case is not so long as those of the species compared, and the narial 

 opening is of a different shape, like a heart but not so pointed, more 

 rounded on the lower side. 



Lagothrix thomasi Elliot. 



Lagothrix thomasi Elliot, Ann. Mag. Nat. Hist., IV, 1909, 8th Ser., 

 p. 245. 



Type locality. Callanga, Cuzco, Peru, 1,500 m. altitude. Type 

 in British Museum. 



Color. Head in front of ears seal brown ; upper parts and sides 

 of body, and arms to elbows grizzled gray and ochraceous, the hairs 

 being ochraceous at base, ringed with black and white and tipped with 

 white ; dorsal line blackish ; hairs on back of neck ochraceous with a 

 single broad subterminal black band and white tips, causing this part 

 to be darker than the rest of the upper parts, except dorsal line ; fore- 

 arms and legs, grizzled black and tawny, the hairs being tawny with 

 subterminal black bar and white tips ; hands and feet black, the hairs 

 with tawny tips; inner side of arms and legs, and central portion of 

 chest and abdomen, black; tail above, and basal portion beneath 

 grizzled gray and ochraceous like back; remainder beneath black. Ex 

 type British Museum. 



Measurements. Size equal to L. lagotricha. Skull: occipito- 

 nasal length, 98; Hensel, 88.4; zygomatic width, 79.4; interorbital 

 width, 59.4; palatal length, 39.6; median length of nasals, 10.7; length 

 of upper molar series, 24; length of mandible, 78; length of lower 

 molar series, 38.5. Ex type British Museum. 



This is a larger monkey than L. ubericola and fully equal in size 

 to L. LAGOTRICHA. The type is an old individual, with teeth greatly 

 worn and blackened. It is much darker than L. ubericola and the 

 base of the hairs ochraceous instead of buff. There are none of the 



