86 QUADRUMANA. 



developed largely in these monkeys. In man, the bone in question gives 

 support to the tongue and is attached to numerous muscles of the neck. 

 In the Howling Monkeys it takes a wider range of duty, and, by a 

 curious modification of structure, forms a bony drum which communi- 

 cates with the windpipe and gives to the voice its powerful resonance. 



The larynx has six sacks connected with it, in which the voice is 

 received ; two of these are of considerable size, and resemble the crop 

 of birds. The tail is long, bare at the extremity, nervous and muscular. 



The Howlers inhabit almost all the countries of South America; 

 even those elevated regions where heavy frosts occur in winter, and do 

 not suffer from the cold rains. Cattle perish, but the first bright day 

 brings out the voice of the HowLERS, and they may be seen climbing to 

 the tops of the trees to dry themselves in the warm sunbeams. 



THE RED AND BLACK HOWLERS. 



The Aluate, or Red Howler, Mycctcs scniculus, has a reddish-brown 

 fur, inclining to yellow on the back; the hair is short, stiff, and uniform. 

 The female is smaller and darker. It inhabits the whole East of South 

 America. 



The Black Howler, Mycctcs Caraya (Plate III), is a native of Para- 

 guay. The hair is long and black, inclining to red at the sides ; in the 

 female, yellowish on the belly. It is rather less than the Red Howler. 



HABITS OF THE HOWLING MONKEYS. 



The habits of the two species are so much alike that the descriptions 

 of travelers appl}- equally to both. Schomburgk gives a lively account 

 of his observations of a herd of Howlers. " I followed the sound, and 

 after great exertions got within view of the troop without being per- 

 ceived. They sat before me on a high tree and performed the most 

 frightful concert that can be imagined, ever}^ beast of the forest seemed 

 engaged in deadly strife ; at times the tones were Hke the grunting of a 

 pig, the next moment the roar of the jaguar as he springs on his prey, 

 then the low, awful growling of that beast of prey when, surrounded on 

 all sides, he recognizes the presence of danger. The performers would 

 stop suddenly, as if a signal had been given, and then quite unexpectedly 

 a singer would raise up his inharmonious voice, and the howling recom- 



