440 



DR. J. E. GRAY ON THE BRADYPODID^E. 



[May 2, 



II. Fur grey, elongate, flaccid, sometimes very indistinctly marbled 



vjith white blotches. 



a. The male with a large yellow soft patch of hair on the back. 

 7. Arctopithecus griseus. (Plate XXXVI.) 



Fur very long, greyish white, scarcely mottled ; under-fur very 

 long and abundant, black or white. Forehead and cheeks yellowish 

 white ; a broad band across the crown of the head and a broad 

 streak from the orbits black. Male with a large yellow patch of 

 soft hair in the middle of the back, with a broad central streak, and 

 varied with blackish brown on the margins. Angle of the lower jaw 

 broad, rounded, not produced beyond the back edge of the condyle. 



Fig. 6. 



Skull of Arctopithecus griseus. 



Arctopithecus griseus, Gray, Ann. & Mag. N. H. 18/1, vii. p. 302. 



Rub. Costa Rica, Cordillera del Chucu, Veragua (Salvin). 



The males and females have a more or less distinct dark dorsal 

 spot, which is only visible when the animal is very carefully examined ; 

 and the general fur shows in some lights indefinite pale blotches on 

 the back and limbs, which are produced by certain dark parts of the 

 under-fur. The upper parts and sides of the head and neck dark 

 brown ; the forehead, the cheeks, and chin white ; this white colour 

 occupies a less space of the chin and cheeks, and is less marked in 

 the males than in the females or young. The black streak through 

 the eye is distinct, is widened out on the sides of the face in the 

 males, but is narrower behind and shorter in the female and 

 young. The under-fur is very abundant and very soft, elongate, 

 pure white, and with black or chocolate-brown in spots, producing 

 rather a mottled appearance. Two of these white spots on the 

 middle of the back are very distinctly marked in the female, and I 

 at first thought they were a good character for a separate species ; 

 but I find, now the specimens are stuffed, that there are similar spots 

 scattered over the bodies of all four specimens. The dorsal spot of 

 the male is pale yellow with a very black central band, paler yellow 



