726 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. 
12; Cc; P38; MS = 36. 
: : 
2—2 I—I 3-3 33 
Alouatta Lacépéde, Tabl. Ordres et Genres Mamm., 1799, p. 4. 
Type Simia belzebul Linneus. 
Mycetes 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. ee 
A. Upper parts black, beneath blacki oi. <s 3ee 4.villosa 726 
B. Upper parts yellowish brown, varying in ex- 
tent. 
a Size largesse Ss s sae ee bees 4. palliata 726 
be Sige sitiall... fox Oe Eek a ee ee ee ee .A. p. mexicana 727 
G.. Dige very small 0 sn ice eee A. p. cotbensis 727 
679. villosa (Mycetes), Gray, Ann. Mag. Nat. Hist., rst Ser., xv1, 
1845, p. 220. 
Vittous Hower. Mono in Guatemala. 
Type locality. Brazil. 
Geogr. 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 (A/ycetes), Gray, Proc. Zodl. Soc., 1848, p. £38, pl. v1. 
ManTLED How er. Congo in Costa Rica; Congo, o’Mono Chaillon 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 
