SEXUAL DIMORPHISM IN CANINE LENGTH OF WOOLLY SPIDER MONKEYS (BRACHYTELES-ARACHNOIDES, GEOFFROY,E. 1806)

We measured canine teeth from 28 woolly spider monkeys (Brachyteles ar achnoides) to assess sexual dimorphism and population differences. The specimens are from the Brazilian states of Bahia, Minas Gerais, Espir ito Santo, Rio de Janeiro, and Sao Paulo. We found strong sexual dimor phism in canine length for individuals belonging to populations south of 22-degrees-00' latitude but no sexual dimorphism in canine length f rom individuals of populations north of 21-degrees-00' latitude. Canin e length did not vary among females of northern and southern populatio ns. However, southern males had significantly longer canines than nort hern males. This geographical difference in canine morphology, togethe r with the presence or absence of thumbs and published accounts of dif ferences in genetics and social structure between northern and souther n populations, suggests that Brachyteles arachnoides may be composed o f at least two subspecies, which appear to be separated by the rivers Grande and Paraiba do Sul and the Serra da Mantiqueira.