1 92 ALLEN'S NATURALIST'S LIBRARY. 



of the Amazon, into which no other species intrudes. They 

 are found, however, from Eastern Guatemala to Paraguay. 



THE HOWLERS. GENUS ALOUATTA. 

 Alouatta, Lacep., Mm. Inst., iii., p. 490 (1801). 

 Mycetes, Illig., Prodr. Syst. Mamm., p. 70 (1811). 

 Stentor, Geoffr., Ann. Mus., xix., p. 107 (1812). 



The characters of the genus Mycetes, which is the only one 

 of the sub-family, are the same as those given above under the 

 sub-family heading. 



The genus contains six well-recognised species. According 

 to Mr. Wallace the red and black species of the Amazon have 

 females of the same colour as the males. Humboldt also re- 

 marks, speaking of the thousands of Arguatoes (M. seniculus) 

 which he observed in the provinces of Cumana. Caracas, 

 and in Guiana, that he never saw any change in the reddish- 

 brown fur of the back and shoulders, either in isolated indi- 

 viduals or whole troops. Many of the species, however, do 

 have the sexes of quite different colours. 



The Howlers are semi-nocturnal in their habits, uttering 

 their cries late in the evening and before sunrise, and also on 

 the approach of rain. ( Wallace?) 



When a Mycetes is shot it always hangs to the tree, even if 

 quite dead, and does not fall till the muscles of the feet and 

 tail relax. 



The species of this genus range through Central America, 

 Colombia, and the Amazonian region, to Southern Brazil, 

 Bolivia, and Paraguay. 



I. THE RED HOWLER. ALOUATTA SENICULUS. 



Simia seniculus, Linn., Syst. Nat, i., p. 37 (1766). 



