648 Bulletin American Museum of Natural History [Vol. LXVI 



Though individual variation and differences in method of preserva- 

 tion seem to account for a high percentage of the differences represented, 

 there is some divergence that is obviously due to age and its attendant 

 wear on the scale surface. This attains extremes in the young animals 

 with rough, unworn scales and in the old individuals in which all scales 

 are smooth and polished through friction between themselves and be- 

 tween the scales and their environment. In both of these age extremes 

 the color, general and local, is lighter. In the young animals this is 

 achieved through the masking occasioned by rugosity and soiling, and 

 in the older individuals, it seems, through the wearing away of the pig- 

 mented layer, though this of course may be only one of the factors 

 responsible. 



The naked skin of the under parts is, in the tanned hides, near warm 

 buff. In his field catalogue Mr. Lang described a freshly killed animal 

 in the following terms: "Nose dull blue-gray, rest of snout and other 

 naked parts on head, pinkish gray, ventral surface grayish white. The 

 iris darkish." 



Scale Topography. — It has been written (1931, Frechkop, p. 7) 

 that the scales of gigantea are without keels, but this is not wholly true, 

 for the two smaller specimens of gigantea in the Congo series, where wear 

 of the scales is very limited, show well-developed and characteristic 

 median keels on the scales of the flanks and the limbs (Plate XXXII, 

 figure 1). These are also prominent in the same areas in the embryonic 

 specimens of the species (Plate XXXIV, figure 1). Keels are also found 

 on the lower flank scales of young specimens of temminckii, however, 

 and it would thus seem probable that these are characteristic of all of 

 the scaly anteaters, and that the early disappearance in the large species 

 is due only to the greater wear to which these terrestrial forms are 

 subjected. 



The shape of the scales in the two species of the Smutsia group is 

 altered by the wearing away of the tip. In the dorsal region the pos- 

 terior scale border is occasionally perfectly transverse, and the scales of 

 both the back and tail appear as though truncated by some artificial 

 process. More commonly the free margin is modified into an elipsoidal 

 arc. 



Scale Number. — Scalation is relatively constant, but not exactly 

 so. The full number of scales appears during uterine life, and modifica- 

 tion in scale count is, it seems, occasioned only by injury. Several 

 individuals which were obviously confined for some time by a devise in 

 the form of a halter have lost the scales in lines where the restraining 



