i86 APES AND MONKEYS. 



chestnut - coloured at their tips ; wliiU' at tlie same time a thick under - I'ui- is 

 developed. It was old individuals with this long silky kind of hair that Dr. Gray 

 described as a distinct species, under the name of the silky howler (J/, laniycr). 



This liowler appears to be mainly a northern form, occurring in Colombia 

 on the west, and in Guiana on the east side of South America; while, according to 

 Mr. Bates, who describes its fur as being of a shining yellowish-red colour, it is the 

 sole representative of the howlers in the Upper Amazon valley. It also occurs in 

 Ecuador ; and, according to Dr. Gray, is represented by a pale variety in Bolivia. 



The red howler is one of the two species of this genus that have been exhibited 

 in the Gardens of the London Zoological Society. It is, however, difficult to keep 

 alive for any length of time, and of two specimens received from the Dekka River, 

 near Cartagena, on August 28th, 1863, the one died on September 25th, and the other 

 on October 7th of the same year. Wiiting of these howlers, which he states are 

 known to the natives as ouarines, and on the Demerara in Guiana are commonly 

 known as red monkeys, the ti'aveller Charles Waterton states " that nothing can 

 sound more dreadful than the nocturnal bowlings of this red monkey. Whilst 

 lying in your hammock amiil these gloomy and innneasurable wilds, you hear him 

 howling at intervals from eleven o'clock at night till daybreak. You would 

 suppose that half the wild beasts of the forest were collecting for the work of 

 carnage. Now it is the tremendous roar of the jaguar, as he springs upon his 

 prey ; now it changes to his terrible and deep-toned growlings, as he is pressed ou 

 all sides by superior force ; ami now you hear his last dying groan ])eneath a 

 mortal wound. Some naturalists have supposed that these awful sounds, which 

 you would fancy are those of enraged and dying wild beasts, proceed from a 

 number of red monkeys howling in conceii;. One of them alone is capable of pro- 

 ducing all these sounds; and the anatomists, on an inspection of his trachea 

 (windpipe), will be fully satisfied that this is the case. When you look at him, as 

 he is sitting on the branch of a tree, you will see a lump in his throat the size of a 

 hen's egg. In dark and cloudy weather, and just before a shower of rain, this 

 monkey will often howl in the day-time ; and if you advance cautiously, and get 

 under the high and tufted trees where he is sitting, you may have a capital oppor- 

 tunity of witnessing his wonderful powers of producing these dreadful and dis- 

 cor<lant sounds. Thus one single solitary monkey, in lieu of having others to sit 

 down an<l listen to him, according to tlie report of travellers, has not even one 

 attendant. Once I was fortunate enough to smuggle myself under the very tree, 

 on the higher branches of wliich was perched a full-grown red monkey. I saw his 

 huge mouth open ; I saw the protuberance on his inflated throat ; and I listened 

 with extreme astonishment to sounds which might have had their origin in the 

 infernal regions." 



The brown howler (il/. ursiniis) is a Brazilian species, apparently 

 found only or chiefly south of the Amazon. Its u.sual colour is a 

 blackish-brown, moi'e or less washed with j-ellow: and some varieties are almost 

 entii-ely yellow, tliis being most marked on the limbs and tail. The howler 

 described as M. fancufi, of which specimens have been exhibited in the London 

 Zoological Society's Gardens, is regarded by Dr. Gray merely as a variety of this 

 species. It has been observed that the specimens of this monkey from the more 



