NO, 1976. 



TREE8HREWS: FAMILY TUPAIID^—LYON. 



31 



Diagnostic characters. — The most generalized member of the family 

 Tupaiidse, mainly characterized by the absence of the specializations 

 of the other members, such as rostrum not excessively elongated, tail 

 not tufted nor close-haired, teeth without unusual development of 

 hypocones or other peculiarities, head without conspicuous markings. 



External cliaracters. — The external form of Twpaia is exceedingly 

 squirrel-like. The natives make no distinction in name between tu- 

 paias and squirrels, calling both tupai. Collectors observe it is some- 

 times impossible to say whether a squirrel or tupaia has been shot until 

 the specimen is picked up. Even experienced workers in museums 

 now and then confuse a tupai skin with a squirrel skin. Aside from 

 the shrew-like snout of Tupaia, a character which is not usually 

 obvious in the average skin, the genus is quickly distinguished from 

 Sciurus hj the absence of the long black whiskers or vibrissse. From 

 the other members of the family Tupaia is distinguished by its rela- 

 tively small ears, finely 

 reticulated naked area 

 of nose, not encroach- 

 ing on haired area of 

 nose, well-haired tail, 

 lack of face markings. 

 A more or less dis- 

 tinctly defined oblicjiie 

 shoulder stripe present. 

 Mammse vary from one 

 to three pairs. For the 

 number and arrange- 

 ment of the footpads 

 see fig. 3, page 32. 





Fig. 2.— Diagram illustrating the ehinarium (1) in the ge- 

 nera Tana and Urog.vle and (2) in the genera Tupaia, 

 Anathana, and Dendrogale. About natural size. 



Cranial characters. — Rostrum moderately short and heavy; dis- 

 tance from the lachr3^mal notch to end of premaxilla is about equal 

 to the distance from the notch to the region of the external auditory 

 meatus ; in some species the posterior leg of the dividers falling behind 

 the opening, and in others in front of it. In the group containing the 

 species Tupaia minor and gracilis, the rostrum is particularly short 

 and stubby and the posterior leg of the dividers reaches to about the 

 end of the pterygoid processes. In the species T. chrysogaster the 

 rostrum is ver}^ slender, but not so much elongated, and the skull as a 

 whole strongly suggests that of the genus Tana. The width of the 

 braincase usually approximately equals the length of maxillary tooth- 

 row, or exceeds it a trifle in most species ; in some of the smaller mem- 

 bers of the genus it exceeds it by as much as 3 or 4 mm. Fenestra in 

 zygoma, large and conspicuous, elongated oval in shape; a distinct 

 supraorbital foramen present; temporal fossa distinctly smaller than 

 orbit. (Fig. 4, page 33.) 



