SENIOCEBUS 179 



SUBORDER 2. ANTHROPOIDEA. 



FAMILY 1. CALLITRICHID/E. 



GENUS SENIOCEBUS. BALD-HEADED TAMARINS. 



I. g; C. lE^; P. S; M.t^ = 32. 



SENIOCEBUS Gray, Cat. Monkeys, Lemurs and Fruit-eating Bats, 

 Brit. Mus., 1870, p. 68. Type Midas bicolor Spix. 

 Tamarin Gray, Cat. Monkeys, Lemurs and Fruit-eating Bats, 

 Brit. Mus., 1870, p. 68. 



Face naked, hairy in young ; no mane ; head in front of ears bald ; 

 ears naked, exposed ; tail not ringed. 



With this genus we enter the Suborder Anthropoidea. The 

 Tamarins all belong to the Platyrrhine or New World Monkeys, and 

 in many respects occupy the lowest rank. They possess but thirty- 

 two teeth, instead of thirty-six as in the Cebid-e and higher Apes, as 

 well as in man, the discrepancy being caused by the absence of two 

 molars in each jaw, only eight in all remaining. 



The Tamarins placed in this work in the four genera Seniocebus, 

 *Cercopithecus, Leontocebus with a subgenus Marikina, and 

 CEdipomidas, are small delicate creatures with silky fur, and long, 

 thick, almost bushy tails. By the earlier writers they were contained 

 either in Callithrix or Hapale with the Marmosets, but are now not 

 considered cogeneric with the species contained in the first of those 

 genera, and the second Hapale, being antedated, becomes a synonym. 

 The chief difference between the members of Callithrix and the 

 species now under consideration is found in the teeth, the canines of 

 the lower jaw being longer than the incisors, a distinction deemed by 

 some Authors as perhaps hardly sufficient to cause the Tamarins to be 

 separated generically from their relatives. Tamarins and Marmosets 

 resemble each other, and the skulls with the large braincase are much 

 alike. Both groups possess but little intelligence, as the cerebrum, in 

 its smooth surface almost lacking in convolutions, would seem clearly 



*See Elliot, in Bull. Am. Mus. Nat. Hist., N. Y., 1911, p. 341. 



