1862.] OF PITHECIA MONACHUS. 327 



As I am not aware of any anatomical observations upon this genus, 

 it appears desirable to put on record some notes made at the dis- 

 section of this specimen. It was not to be expected that any striking 

 character would be found in which it would differ from animals of 

 allied genera ; the principal point of interest, in fact, was the brain, 

 a description of the form and convolutions of which has hitherto been 

 a desideratum, being one of the few omitted in M. Gratiolet's great 

 work on the Cerebral Folds of the Primates. 



The animal died in the Gardens of the Zoological Society, on the 

 24th of October, 1862, after having lived there about a fortnight, 

 during which time Mr. Wolf was able to make the characteristic 

 sketch which accompanies this communication (PI. XXXVII. ). 



It was a female, nearly adult. All the permanent teeth were in 

 place in the lower jaw ; but the posterior upper molars had not cut 

 the gum on either side. The state of emaciation to which it was re- 

 duced could scarcely be exceeded. In this condition the weight was 

 19 ounces avoirdupois. The dimensions were as follows : — 



inches. 

 Length from the vertex of the head to the root of the tail . 1 1 



Length of tail (including 1| inch of hair only) 18 



head, from tip of nose to occiput 2-9 



Greatest breadth of head 1| 



Length of upperarm 3^ 



forearm , 3g 



hand 2| 



thigh 41 



leg 4| 



foot 4 



The large hood of long loose hair upon the upper part of the 

 head, neck, and shoulders, from under which the comparatively bare 

 face emerges, gives a very peculiar appearance to the general phy- 

 siognomy. The face is long and narrow ; the nose large and full, its 

 breadth '6 inch ; the nostrils wide apart, quite lateral in situation ; 

 the chin rapidly retreating. The eyes of moderate size, their axes 

 directed straight forwards ; the width of aperture •4.5 inch ; the dia- 

 meter of the iris "3 inch ; colour of the iris hazel-brown. The skin 

 of the face is of a dark purplish brown, almost black upon the nose, 

 and paler around the eyes ; it is sparingly covered with short coarse 

 hairs of a whitish colour. Rather more than half an inch of the 

 forehead is clothed with these short hairs, directed upwards in the 

 middle, and outwards on the sides. Above this comes the hair of the 

 hood, directed forwards. On each cheek is a well-marked patch of 

 yellowish white hair, directed downwards and forwards, terminating 

 in front by a distinct line extending from the inner canthus of the 

 eye to below the angle of the mouth. In front of this line the dark 

 colour of the skin predominates over the white of the short scattered 

 hairs, except along the margin of the upper lip, where these are 

 longer and more abundant. The ears are large, and roundish in form, 

 quite naked, and of the same colour as the skin of the face ; a consi- 

 derable patch of skin behind them is free from hair. 



