Memoir upon the Apes with irnperfeci Hands ^ ^ 



ference between thechamek and the coaita, that I was forced 

 to consider them as two distinct species ; and in order to 

 verify my first opinion on this subject, I took the cranium 

 from tlie carcase sent to me by M. Martin, in order to com- 

 pare it with that of the coaita. These two crania appeared 

 to me to be sensibly different : that of the chamek is larger, 

 shorter, flatter towards the suture of the parietal bones, and 

 more swelled at the temples. The coronal bone is a little 

 depressed towards the sides, in such a manner that the 

 chamek has a slight tuft ; the forehead of the coaita, on the 

 contrary, is perfectly rounded. The lower jaw is in particular 

 much longer ; its lower edge is straight, while it is arched 

 in the coaita : lastly, the ascending branches of it arc so ex- 

 tended that we are led to think that they might, as in the 

 alouati, serve as a kind of partition to a hyoidal bone with a 

 cavernous base. 



The thumb is very different in the two species : in the coaita 

 the metacarpal bone is, for the most part, as long as the half 

 of its neighbouring one, and the phalange that terminates it 

 is so small, that it only forms a fifth part of the length of 

 this first bone ; these two bones are slender in proportion, 

 so that they are lost in the common integuments, without 

 showing any traces externally. In the chamek there are the 

 same bones : the principal difference is in their thickness ; 

 the metacarpal bone is, besides, a little longer. The first 

 and the only phalange is longer ; it makes nearly a third oi" 

 it; it is much larger, particularly towards the extremity. It 

 is this phalange which, detaching itself from the second 

 metacarpal bone, constitutes the thumb of the chamek ; 

 we see it is very short, ar>d that it is not complete, inso- 

 much as it wants the second phalange, and the nail whieli 

 terminates the latter in all the other apts. 



The chamek is generally a little different from the coaita; 

 it is covered, like tlie latter, with r(jugh .-md coarse hair, 

 dry, and a deep black; its face is naked and of a mulish 

 colour, as well as the ears ; the iris of the eye is brown, and 

 surrounded by a small yellowish circle: besides, the hairs 

 of liie arm and fore-arm are in these two species directed 

 towards tht; hand, and those uf the head towards the fore- 



hcud. 



