When my friend Mr. C. W. Beebe was in Borneo he made persistent efforts to secure for me specimens of the rare pen-tailed tree-shrew (Ptilocercus lowii). Failing in this, he obtained the loan of a skin and skeleton of this animal from the Rajah of Sarawak, and these he has very kindly intrusted to me for study and description.
Ptilocercus and its ally, Tupaia, together constituting the family Tupaiidse of the suborder Menotyphla, are of peculiar interest, because they appear to bridge over to some extent the gap that separates Insectivores from Primates. They are arboreal in habit, and Tupaia is said to be lively, active, and squirrel-like, both in appearance and in habit.
Certain anatomical resemblances shown by Tupaia to the Lemurs have been noted from time to time by various authors, but until recently the Tupaiids have been studied far less thoroughly than other families of Insectivores. . . .