Mr. J. E. Gray on the Howling Monkeys. 219 



redder. It agrees well with the M. stramineus, Spix, t. 31. The 

 young female is yellow-brown, darker on the shoulders; the 

 adult is black slightly washed with yellow from the small yellow 

 tips to the blackish hairs, and the other male is just intermediate 

 in colour between the two females ; the latter nearly agrees with 

 M. fuscus, Spix, t. 30. In the Zoological Society's museum are 

 two females from British Guiana, which are of a uniform dark 

 brown, with the hair between the shoulders very minutely yellow- 

 tipped. 



2. The Golden Howler, Mycetes seniculus, Kuhl. Simia seniculus, 

 Linn. Royal Monkey, Penn. ; Buffon, N. H. Supp. vii. t. 25. 



Reddish chestnut; middle of the back golden yellow; hair 

 one-coloured to the base, short, rather rigid, without any under- 

 fur ; of the head short. 



Inhab. Brazils. 



The Museum collection contains three adult males : we have 

 no females of a different colour that would suit them, and we 

 have none that have not their proper-coloured mates. 



3. The Silky Howler, Mycetes laniger. 



Reddish chestnut; middle of the back golden yellow; hair 

 elongate, very soft and silky, dark brown at the base, golden or 

 chestnut at the tip, with a close under-fur ; of the head rather 

 elongate. 



Inhab. Columbia. Purchased at Paris. 



We have two males and two females of this species, an adult 

 and half-grown specimen of each sex ; one of the females has the 

 end half of the tail decidedly rather paler, so that in this parti- 

 cular it agrees with M. chrysurus of M. I. Geoffroy ; but the other 

 specimen varies a little in the intensity of the colour of this part, 

 so that I cannot consider it of any importance. 



4. Black and Yellow Howler, Mycetes bicolor. 



Black ; hair rather rigid, uniform black, sides of the loins varied 

 with yellow ; hair of this part black, with a broad subcentral red- 

 dish-yellow band. 



Inhab. Brazils. 



We have an adult male ; it is much like M. Caraya in external 

 appearance, but the hair of the forehead is decidedly reflexed, 

 marking a distinct ridge. It is most like M. seniculus in texture 

 of fur,. &c., but vcijy ^^ifFercnt-coloured. If it had not been of the 

 same sex and age 5|^pur specimen of that species, I might have 



been inclined to have regarded it as identical 



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