7-Jii ALOUATTA. 



leaves and fruits. They vary wonderfully in color, both among 

 individuals and between the sexes, while some of the races, separated 

 on the hues of the fur, or difference in size, have a precarious and 

 unsatisfactory scientific standing. In intelligence these monkeys have 

 a very low rank. The species associate in small groups, and the 

 habits do not apparently vary among the recognized forms. They 

 range from Central America to southern South America. 



174. Alouatta. Howling Monkeys. 



Alouatta Lacepede, Tabl. Ordres et Genres Mamm., 1799, p. 4. 

 Type Simia belzebul Linnaeus. 



Mycctes Illig., Prodr. Syst. Mamm. Av., 1811, p. 70. 



Occipital region of skull truncate; rami of mandible enormously 

 developed; hyoid greatly inflated; lower incisors vertical, canines 

 powerful; claws convex, strong. 



KEY TO THE SPECIES. PAGE 



A. Upper parts black, beneath black ................. 4. villosa 726 



B. Upper parts yellowish brown, varying in ex- 

 tent. 



a Size large .................. ' ................ A . palliata 726 



b. Size small .............................. A. p. mexicana 727 



c. Size very small .......................... A. p. coibcnsis 727 



679. villosa (Mycctes}, Gray, Ann. Mag. Nat. Hist., ist Ser., xvi, 



1845, P- 22 - 

 VILLOUS HOWLER. Mono in Guatemala. 



Type locality. Brazil. 



Gcogr. Distr. Guatemala and Honduras, Central America, into 

 South America. 



Color. Uniform black; hairs beneath ears brownish at base. 



Measurements. Total length, 1650; tail, 630; foot, 128. 



680. palliata (Mycetes), Gray, Proc. Zool. Soc., 1848, p. 138, pi. vi. 

 MANTLED HOWLER. Congo in Costa Rica; Congo, o'Mono Chillon in 



Nicaragua. 



Type locality. Caracas, Venezuela. 

 Geogr. Distr. Nicaragua to South America. 



Genl. Char. Hair of forehead forming a slight crest ; beard slight . 

 Color. Very variable. Black; middle of back and upper part of 



