PROCEEDINGS OP THE NATIONAL MUSEUM. vol. 45. 



Geoffrey was naturally quite unaware of the existence of Ellis's 

 manuscript notes and drawings. Since Diard's and Raffles's time 

 the group has become better and better known and its geographic 

 range widely extended. The most important discoveries in regard 

 to the group since 1821 have been the announcement of the genus 

 Ptilocercus by Gray/ 1848, of the group now called Dendrogale by 

 Schlegel and Miiller/ the discovery of treeshrews in the Philippine 

 Islands by Whitehead, about 1879,^ now formmg the genus Urogale, 

 and the discovery of treeshrews in India by W. Elliot, about 1849.* 



DEFINITION AND RELATIONSHIPS. 



The Tupaiidse are diurnal insectivorous mammals characterized 

 by a general squuTel-like aspect, more or less arboreal habits, orbits 

 completely encircled by bone, alisphenoid canal present, malar bone 

 with a more or less enlarged perforation, separate radius and ulna, 

 and separate tibia and fibula, dental formula / § C }, Pm f M. f , 

 upper molars with typical W pattern. The family is composed of 

 two very distinct groups for a long time regarded as genera, the 

 typical members of the family, Tupaia and the aberrant Ptilocercus. 

 The old genus Tupaia has gradually been seen to be a composite 

 genus, and up to the present time has been divided into three sepa- 

 rate genera: Tupaia, Dendrogale, Urogale. In the present paper 

 two more genera are recognized. These genera are now for the first 

 time grouped to form the subfamily Tupaiinse. The single genus 

 Ptilocercus is here regarded as forming the subfamily Ptilocercinse. 

 Eylomys of the Erinaceidse was formerly associated with the tree- 

 shrews, but was removed in 1874 by Anderson.^ 



TuPAIINiE. 



Tail bushy or close-haired tliroughout 



its entire extent. 

 Ears small and cartilaginous. 

 Footpads of moderate development. 

 Supraorbital foramen well developed. 

 Foramen rotundum entirely distinct 



from sphenoidal fissure. 

 Second upper incisor unicuspid. 



Upper molars with well-developed bifur- 

 cated mesostyles. 



Upper molar teeth without a distinct 

 cingulum. 



Lower molar teeth without a cingulum. 



PTILOCERCIN.a;. 



Tail with terminal portion distichously 

 tufted, naked, and scaly basally. 



Ears large and membranaceous. 



Footpads relatively large and soft. 



Supraorbital foramen absent. 



Foramen rotundum confluent with sphe- 

 noidal fissure. 



Second upper incisor with a distinct 

 posterior cusp. 



Upper molars without mesostyles. 



A distinct cingulum encircles the upper 



molar teeth. 

 Lower molar teeth with a cingulum on 



outer surface. 



1 Proc. Zoo!. Soc. London, 1848, p. 23. 



2 Verb. Nat. Gesch. Nederl. Overz. Bezitt., p. 167, 1839-44. 



8 Thomas, Ann. Mag. Nat. Hist., ser. 6, vol. 9, p. 250, March, 1S92. 

 * Waterhousc, Proc. Zool. Soc. London, 1849, p. 107. 

 6 Trans. Zool. Soc. Londan, vol. 8, 1874, pp. 453-467. 



