INTRODUCTION xxiii 



intelligent species, delicate of frame and constitution, unable to bear 

 captivity, and soon succumb when taken from their accustomed environ- 

 ment. Callitrichid.e contains six genera with about sixty species 

 and subspecies. The members of this Family have only thirty-two teeth 

 and in this respect resemble the species of the Old World, and differ 

 from the rest of the Monkeys indigenous to the western hemisphere. 

 The first genus is Seniocebus with three species, with the head partly 

 bald, and long occipital crest, and without a mane or ruff ; next Cer- 

 COPITHECUS with three species having a mantle ; then Leontocebus 

 having nineteen species, possessing a rufif on neck, and fourth, CEdi- 

 POMIDAS with three species having the head crested and the hairs on 

 the nape elongate. The fifth genus is Callithrix with thirteen species. 

 These are small creatures, among the most delicate of all the members 

 of the Order, have small canines, tails with long hair, and the angle 

 of the mandible expanded as in Pithecia. Callicebus the sixth genus 

 has twenty-two species, closely allied to the previous genus, and 

 agreeing with it in certain of its characteristics. 



We now come to Monkeys that are distinctively American with 

 one pair of extra premolars in both jaws, the nostrils directed outward, 

 and the prehensile tail. They are all included in the Family Cebid-e 

 with its four Subfamilies. The first of these is Alouattin^ having 

 but one genus Alouatta with eleven species, and two subspecies, some 

 of them being the largest in size of the New World Monkeys. They 

 are of low intelligence, morose in disposition, heavy in body and with 

 a wonderfully powerful voice. The second Subfamily. Pithecin.e, 

 containing the Sakis, Uakari and Squirrel Monkeys, has three 

 genera the first of which is Pithecia with eight species. These are 

 animals of moderate size, of a more slender figure than the species of 

 Alouatta, with the hair on head, frequently standing upright, long 

 and thick and with a median part. A thick beard hangs from the 

 chin, especially noticeable in the male, and there is also a lengthened 

 bushy tail. In certain species the hair of head is coarse, loosely set, 

 and is directed forward forming a kind of hood around the face. The 

 second genus is Cacajao with only three species characterized by 

 having the face and a large portion of the head naked and brightly 

 colored, becoming more intense and vivid when the animal becomes 

 excited. The tail is very short and the mandible is dilated posteriorly. 

 The *"cascum in C. calvus is upwards of ten inches along the greater 

 curvature ; it is separated from the colon by a very marked constriction ; 



♦Beddard, Proc. Zool. Soc. Lond., 1887, p. 119. 



