138 ALLEN'S NATURALIST'S LIBRARY. 



THE TAMARINS. GENUS MIDAS. 

 Midas, Geoffr., Ann. Mus., xix., p. 120 (1812). 



This genus differs from the preceding only in the characters 

 of some of the teeth. The canine teeth in the lower jaw are 

 longer than their neighbouring incisors; but, as has been 

 pointed out by Prof. St. George Mivart, it is a question whether 

 this generic distinction can be maintained, as an intermediate 

 condition exists in some forms. 



For the convenience of description the species of this genus 

 have been divided into two groups (a) those with long hair 

 on the head and neck, and (b) those with short hairs on the 

 back of the head. The number of species in the latter group 

 is greater than in the former ; and they are further divided 

 into those with, and those without, white lips. 



I. THE SILKY TAMARIN. MIDAS ROSALIA. 



Siffiia rosalia, Linn., Syst. Nat, i., p. 41, pi. i. (1766). 

 Midas rosalia, Geoffr., Ann. Mus., xix., p. 121 (1812). 

 Leontopithecus rosalia. Gray, Cat. Monkeys Brit. Mus., p. 65 



(1870). 

 Hapale rosalia^ Schl., Mus. Pays Bas, vii., p. 250 (1876). 



Characters. This is the first species of the long-whiskered 

 and maned group ; fur soft and silky ; tail equal in length to 

 the body, bushy at the tip ; hair round the face and on the 

 back of the neck very long, forming a conspicuous ruff. Face, 

 hands, and feet purple; general colour of the hair golden 

 yellow, more or less red, and glossy. 



These animals are said to possess an air-sac in the throat, at 

 the back of the trachea (or windpipe), as in Ateles. Length, 

 1 1 inches ; tail, 1 2 inches. 



