T56 Lloyd's natural history. 



In some species the upper part of the head has a shade of 

 yellow, caused by the colour of the lower half of the hairs 

 showing through the black tips. 



Distri"bution. — Bolivia ; Veragua, Central America ; and the 

 warmer regions of Costa Rica, where it inhabits the humid 

 forests. 



III. THE COMMON SQUIRREL-MONKEY. CHRYSOTHRIX 



SCIUREA. 



Simia sciurea^ Linn., Syst. Nat., i., p. 43 (1766); Humb., 



Obs. ZooL, p. 334 (var. cassiquiarensis). 

 Callithrix sciureus, Geoffr., Ann. Mus., xix., p. 113 (1812). 

 Saimiri sciureus^ Cuv., Reg. An., p. 103, pi. i (1829) ; Schl., 



Mus. Pays Bas, vii., p. 242 (1876). 

 Chrysothrix lunulafa, Geoffr., Arch. Mus., iv., p. 18 (1844). 

 Chrysothrix sciurea^ Wagner in Schreb., Saugth. Suppl, v., 



p. 120, pi. 9, (1855); Gray, Cat. Monkeys Brit. Mus., p. 



53 (1870) ; Sclater, R Z. S., 1880, p. 395. 

 Chrysothrix nigrivittata, Wagn., Abh. bay. Ak. Miinchen, 



v., p. 461. 



Characters.— Smaller than the two preceding species ; foce 

 greyish-white ; chin round and prominent \ head blackish- 

 grey ; back grey, or grey washed with gold, the basal part of 

 the hairs golden and the tips black ; outer side of the fore-arm 

 yellow; tail long, slender, grizzled grey, with the tip black. 

 Length of the body, 10 inches; of the tail, 14 inches. 



Certain females, examined by Dr. Sclater, had a distinct 

 black line along the side of the crown above each ear and ex- 

 tending in front, down the side of the face, nearly to a level 



