258 ALOUATTA 



FAMILY 2. CEBID/E. 



Subfamily 1. Alouattinae. 



GENUS ALOUATTA. HOWLING MONKEYS. 



ALOUATTA Lacepede, Tabl. Div. Sous-div. Ordres et Genres, Marara., 

 1799, p. 4. Type Simla beelzebul Linnaeus. 

 Mycetes Illig., Prodr. Syst. Mamm. et Avium, 1811, p. 70. 

 Stentor E. Geoff., Ann. Mus. Hist. Nat. Paris, XIX, 1812, p. 107. 



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Head pyramidal; body thick, heavy; face naked; chin bearded; 

 tail long, prehensile, naked at tip ; thumb opposable. Skull : braincase 

 depressed; occipital region truncate; angle of mandible enormously 

 developed ; lower incisors vertical ; canines rather strong ; claws convex, 

 powerful ; hyoid greatly inflated. 



This subfamily has but one genus, embracing the largest species of 

 monkeys found in the New World. Their body is thick-set and heavy, 

 the mandible at the angle is very deep and massive, the throat is large 

 and thick, and the larynx extraordinarily developed. The basihyal is 

 greatly enlarged, and is expanded into a bony capsule which is lined 

 by a continuation of the thyroid sac, and so the animal is able, by 

 means of this peculiar formation, to produce the great volume of sound 

 for which it is noted, and from which the trivial name of Howling 

 Monkey is derived. The tone is deep and far reaching, resounding 

 through the forest for an estimated distance of three miles. The tail 

 is long and prehensile, but partially naked, and while of considerable 

 advantage to the animal for grasping, does not attain the sensibility 

 and extreme mobility of the same organs of the species of Ateleus, 

 whose tails are equal in their service to a fifth hand. The thumb of 

 the Howling Monkey is well developed and opposable. The face is 

 naked, and a heavy beard hangs beneath the chin, especially thick in 

 old males. Their movements are slow and their tempers sullen, and 

 the animal is practically untamable and soon dies when held in cap- 

 tivity. Their intelligence is of a very low order, and altogether the 

 animals of this genus are among the least attractive of the Primates. 



