102 



MR. R. I. POCCCK ON THE EXTERNAL 



In Alouatta and Lagothrix the hand is relatively larger and its 

 digits are longer as compared with the foot than in the genera 

 previously mentioned, and the space in the hand between digits 

 2 and 3 is markedly greater than between digits 1 (pollex) and 2 

 or 3 and 4. The hands are thus in a sense zygodactylous, like 



Text -figure 7. 



A. Right hand of Alouatta viUosa, j'oung 



B. Right foot of the same. 



C. Extremity of tail of Ateles ater. 



the paws of Phascolarctos and of Cusci(,s amongst the Marsupials, 

 there being a grasping interval between digits 2 and 3 instead of 

 between digits 1 and 2 as in Lemurs and Catarhine Monkej^s *. 



* From a photograph of a living Tithecia pifJiecia I judge that there is a wide 

 space between digits 2 and 3 in tliat genus also. 



