1907.] MONKEYS FROM THE AMAZONIAN REGION. 97 



Monkey plate, presented to the Zoological Congress at Berne and 

 now being reproduced for a separate publication, it is especially- 

 noticeable that the adult coat is distinguished by the deep blackish- 

 brown colour of the anterior part of the body. 



Briefly described, the colour of a typical adult male is as 

 follows : — 



Dorsal aspect of anterior part of body, as far back as behind 

 the shoulders, of a uniform sooty brownish-black. On sepai-ating 

 the fur, two-thirds of the length of the hairs is lighter, greyish 

 or dirty white near the roots, pale greyish-brown outwards, the 

 outer third shading into the above-mentioned brownish-black, 

 without presenting any tendency to zonal arrangement. The 

 posterior part of the body presents a mottled appearance, due to 

 the intervention of yellowish-reddish zones. On sepaiuting the fur 

 in this region, two-thirds of the length of the hair is quite uni- 

 form dark ; the last third is about equally divided between the 

 light zone and a black terminal one. 



Singularly deep rusty-red are the rump and thighs. This is 

 due to the absence of the dark terminal zone of the hairs in 

 this region, each hair being black at its base, and the terminal 

 third entirely rusty. Tail, arms, and feet black. 



Dorsal and ventral aspects are noticeably divided by a lateral 

 rusty-red stripe of shorter hairs on each side, running from the 

 arm-pit to the flank. The real median ventral stripe, wider than 

 the just-mentioned lateral one, again assumes the dark brown 

 colouring of the anterior part of the body. 



In the face the most salient features are the white eyebrows, 

 meeting in the median line at the base of the nose, forming 

 a very striking double crescent. Circumbuccal zone whitish, 

 more extensive than in all the preceding species, but not so 

 sharply outlined. 



Midas pileatus Is. Geoffroy et Deville. 



This species was figured in 1848 by Geoffroy in the ' Archives du 

 Museum,' vol. v. pi. 31, and described under the name of " Tamarin 

 a calotte rousse," p. 569. Up to the time of my paper read at 

 Berne, at the International Zoological Congress, it seemed to me, 

 judging from the literature within my reach, that it was repre- 

 sented only by the single original specimen, coming from the Rio 

 Javary, and preserved in the Paris Museum. (I saw it there 

 some days before, without a label, stowed away on a side-shelf.) 



At that time we had obtained from the upper River Purus two 

 other specimens, a pair. This splendid species has its chief 

 distinguishing marks in the cinnamon-coloured scalp-patch, the 

 brownish-black general colour, and the sharply outlined white 

 circumbuccal zone, including the nostrils, which are completely 

 surrounded by a narrow white band. 



Being in London for the Meeting of the Fifth International 

 Ornithological Congress in July 1905, Mr. Oldfield Thomas, of the 



Proc. Zool. Soc— 1907, Ko. YII. 7 



