5 56 MARMOSETS 



structure than they have. The Platyrrhines seem to stand at 

 the base of the series. This is another example of the existence of 

 archaic creatures in South America. 



Group I. PLATYBBHINA. 



Fam. 1. Hapalidae. — We may begin the account of the 

 Platyrrhine Monkeys with the Hapalidae or Marmosets ; for this 

 family is structurally lower than the rest. They have thirty-two 

 teeth, arranged as in the following formula : I# C^ Pm | M|- = 32. 

 The molars have three main tubercles, and not four as in the 

 higher forms. The digits are for the most part clawed, not 

 nailed, as in the higher types ; the great toe alone bears a flat 

 nail. The tail, too, is ringed, a condition which is characteristic 

 of many of the lower groups of mammals, but not of the higher 

 Apes. The cerebral hemispheres are smooth, but this is a matter 

 rather connected with their small size than with low zoological 

 position. The tails of the Marmosets, unlike those of so many 

 other American Monkeys, are not prehensile though they are 

 long. 



The genus Hapah is broadly distinguished from the other 

 genus, Midas, by the fact that the lower incisors slant forwards 

 as in the Lemurs. They are small, soft -furred, long -tailed 

 Monkeys, familiar to every one. There are some seven species, 

 which are entirely restricted in range to Brazil, Bolivia, and 

 Colombia, one species only, H. pygmaea, extending northward into 

 Mexico. 



Of Tamarins, genus Midas, there are rather more species — 

 about fourteen. They are South and Central American in dis- 

 tribution. Since both these genera are arboreal in habit, it is 

 extraordinary that they have not the prehensile tails of their 

 American allies. As, however, the late Mr. Bates observed an 

 individual of the species M. nigricoUis fall head-foremost from a 

 height of at least 50 feet, alight on its feet, and run off as if 

 nothing in particular had occurred, it is evident that no extra 

 prehensile powers are absolutely necessary. Some of the Tamarins 

 have a long mane ; this is well seen in Jf. rosalia, or rather in 

 M. leoninus, which, if not identical with it, is at least very closely 

 allied to it. Tlie name is obviously derived from the character 



