NO. 1976. 



TREESHREW8: FAMILY TUPAIID^E—LYON. 



33 



pair of upper incisors and not of the first pair, as seems to be the 

 tendency in the genus Tupaia. The upper canine in Tupaia is 

 moderately well developed, 

 and usually with only one 

 root, except in certain anom- 

 alous cases. Its crown 

 always projects distinctly 

 beyond the level of the ad- 

 jacent premolar. The lower 

 canine is relatively better 

 developed than the upper 

 and always projects con- 

 spicuously above the levels 

 of the adjacent premolar and 

 incisor. In the group of 

 species with the enlarged 

 central incisors and reduced 

 third lower incisor, the lower 

 canine is relatively very 

 much enlarged and stands 

 very high above the man- 

 dibular toothrow. At first 



Fig. 4.— Tupaia glis feekuginea, X 1, Cat. No. 114548. 

 U.S.N.M. Tapanuli Bat, Sumatra. 



sight -this development of the lower ca- 

 nine appears to be a valuable group char- 

 acter, but one encounters specimens or 

 species where it is quite impossible to 

 decide whether the lower canine is of the 

 enormously developed type or not. Its 

 greatest absolute and relative develop- 

 ment occurs in Tupaia nicoharica. In 

 the case of T. cuyonis it is difficult to say 

 whether the canine is unduly enlarged. 

 There are three pairs each of upper and 

 lower premolars. The first of each are 

 small and almost functionless ; the others 

 increase in size and complexity from be- 

 fore backward. The last deciduous pre- 

 molars have the same form as the typical 

 molars. Upper and lower molars, three 

 pairs of each; the first and second upper molars with the hypocones 

 always present, but rather poorly developed. See fig. 5 above. 

 80459°— Proc.N.M.vol.45— 13 3 



Fig. 5.— Tupaia glis feeruginea up- 

 per AND LOWER TOOTHEOWS X 2|, 



Cat. No. 114548, U.S.N.M. Tapa- 

 nuli Bat, Sumatra. 



