THE MARMOSETS AND TAMARINS. I 29 



and one of the Night-Apes (Nyctipithectis vociferans] extends 

 beyond Colombia, in South America." 



"None of the South American Monkeys appear to pass west 

 of the Andean chain of mountains south of Ecuador, and even 

 north of the Peruvian boundary the number of such transgres- 

 sional forms is very limited. Indeed, even among the wooded 

 slopes, a habitation along the basal line of the mountain axis 

 seems to be much preferred. The greatest altitude at which 

 Monkeys were observed by Tschudi in Peru was 3,000 feet 

 (Lagothrix humboldti) Ateles ater and Cebus robustits were 

 found at 2,500 feet. On the other hand, Salvin and Godman 

 state that in the district of Vera Paz, in Guatemala, the ' Mono ' 

 or Howler is most abundant at an elevation of 6,000 feet; and 

 on the Volcano of Atitlan, in the same country, Mr. Salvin 

 found troops of the Mexican Spider-Monkey (Ateles vellerosiis) 

 in the forest region of 7,000 feet elevation. 



"The range of the Marmosets and Oustitis (ffapalidce.) is 

 nearly co-extensive with that of the Monkeys proper." (Heil- 

 trin.) The Pigmy and the Silky Marmoset range as far north 

 as Mexico. 



THE MARMOSETS AND TAMARINS. FAMILY 



Of the New World, or Platyrrhine, Apes, the Marmosets come 

 to be described first, as they have many characters which mark 

 them out as the lowest of the Anthropoidea, and rank them 

 nearer to the Lemuroidea than any of the others. They are 

 specially characterised by having only thirty-two teeth, their 

 dental formula being If, C}, Pj|, Mf . In the actual number of 

 their teeth they agree with their Eastern relations, but with this 

 3- v. i K 



