30 



MR. R. I. POCOCK OX THE EXTERNAL 



about two-thirds the length of the naked portion. In the speci- 

 men examined the third and fourth digits were approximately 

 equal both on the hands and feet (text-fig. 5, A, B). 



The hands and feet of the Indrisidse, as figured and described 

 by Milne-Edwards and Grandidier, show some interesting pecu- 

 liarities suggesting more complete adaptation to arboreal life than 

 in the Lemuridce. In Propithecus the digits of the hand are 

 hardly more webbed than in Lemur, but the palm is narrower, 

 especially posteriorly, where the pollex arises. The pads appear 

 to be very little differentiated, and the absence of the "ball" of 

 the thumb indicates a feeble grip for that digit. In Lichanotus 

 (Avahis) the ball of the thumb is better developed, but the palm 

 of the hand is apparently longer than in Propithecus, the second 



Text-figure 6. 



A. Foot and B. Hand of Chiromys-, X f. 



digit, which is very short, being widely separated from tlie 

 pollex. The third, fourth, and fifth are long and united by 

 narrow webbing approximately to the ends of the first phalanges. 

 In Indris also the hand is long and slender, with a wide space 

 between the long weak pollex and the second digit. The latter, 

 however, is not so short as in Lichanotus, and is united to the 

 third, as the third is to the fourth and the fourth to the fifth, by 

 integument permitting but slight divarication of these digits and 

 increasing in appearance the elongation of the palm. 



In the feet there is less variation. The hallux is normally 

 elongated, but is slender from base to apex without the muscular 

 development seen in other Lemuroidea, and the digits are webbed 



