130 ALLEN'S NATURALIST'S LIBRARY. 



difference, that in the latter the pre-molars are two, and the 

 molars three, above and below on each side. Their flattened 

 nose, with its wide partition between the nostrils, and their 

 non-prehensile bushy tails, are also distinguishing characters. 

 The face is nude, the ears large and sometimes fringed. Their 

 hind-limbs are proportionately larger and longer than their fore- 

 limbs, while the nails of their fingers and toes are not flattened 

 as in the Old World Apes, but all form sharp curved claws, 

 except on the much shortened great toe. The thumb is elon- 

 gated and lies parallel, but quite unopposable to, nor indeed is 

 it separable at will from, the rest of the digits. The fore-foot, 

 consequently, " is a mere paw, and the term 'hand' is not applic- 

 able to it." . . . The plantar surface of the hind-foot "is very 

 long, and the digits are very short. It follows from these facts 

 that the term ' quadrumanous ' is not applicable in any sense 

 to the Marmosets." (Huxley.} These animals have no callosi- 

 ties over the ischial (or buttock) bones, and no cheek-pouches. 

 In their smooth and rounded skull superciliary ridges are con- 

 spicuously absent ; and the ear-capsules have, as has been 

 already observed, no external bony canal for conducting sound 

 vibrations to the inner ear. The hyoid bone resembles that of 

 the Lemurs. 



This family has been divided into two genera, distinguished 

 from each other only by a variation in the relative length of 

 their incisor and canine teeth, which is so slight as to render it 

 doubtful whether these differences really warrant the generic 

 separation of the two groups. As, however, the distinction has 

 been maintained by nearly all writers upon these animals, the 

 arrangement has been followed here, and the various species of 

 the family will be described as true Marmosets (Hapale) and 



