NO. 1976. 



TREE8HREW8: FAMILY TUPAIID^—LYON. 



Genera and their types. Genus and its type. 



Tupaia Raffles, 1821, Tupaia/erruginea. Ptilocercus Gray, 1848, Ptilocercus lowii. 

 Anaihana, new, Tupaia ellioti. 

 Dendrogale Gray , 1848, Tupaia murina. 

 Tana, new, Tupaia tana. 

 Urogale Mearns, 1905, U. cylindrura ( = 

 T. everetti.) 



The nearest relatives of the Tiipaiidse are the Macroscelididae, 

 terrestial Insectivores of Africa. Many authors ^ place the two 

 families in a siiperfamily or subordinal gi'oup, the Menotyphla or 

 Tupaioidea as distinguished from all the other living Insectivores the 

 Lipotyphla. 



This grouping appears to me to be a natural one, and the differences 

 that we now find between the Tupaiidee and the Macroscelididse are 

 in large measure due to the very different modes of life of the two 

 families, the Tupaiidse bemg quite arboreal in their habits, and the 

 Macroscelididae, terrestrial and saltatorial. The geographic distri- 

 bution of the two families taken together show many resemblances 

 to the present day distribution of the Tragulidse, rhinoceroses, 

 elephants, anthropoid apes, Cercopithecidge, and Megachiroptera, 

 a circumstance lending some weight to their probable common origin. 

 In spite of their great difference there is scarcely an osteological 

 structure in the Macroscelididie that does not have some counterpart 

 m the Tupaiidse, and the opposite, the most conspicuous difference 

 being the absence of the alisphenoid canal in the former and its 

 presence in the latter, and the complete bony orbit of the Tupaiidae 

 absent in the African family. The skull of the Macroscalididse bears 

 most general resemblance to that of Ptilocercus, and it is interesting 

 to note that a supraorbital foramen is lacking in both, but is a con- 

 spicuous feature of the Tupaiin^e. The main differential points 

 between the two families are seen in the following table: 



TUPAIID^. 



Alisphenoid canal present. 



Supraorbital foramen present (except in 



Ptilocercus) . 

 Orbit completely surrounded by bone. 



Radius and ulna separate bones. 

 Tibia and fibula separate bones. 

 Metatarsals not unusually elongated. 

 Premolars, 3 above and 3 below. 

 Molars, 3 above and 3 below. 



Macroscelidid^. 



Alisphenoid canal absent. 

 Supraorbital foramen absent. 



Orbit not completely surrounded by bone, 



even postorbital processes lacking. 

 Radius and iilna fused. 

 Tibia and fibula fused. 

 Metatarsals unusually elongated. 

 Premolars, 4 above and 4 below. 

 Molars, 2 above and usually 2 below 

 (sometimes 3 below). ^ 

 > Weber, Die Saugetiero, 1904, p. 377. Gregory, Bull. Amer. Mus. Nat. Hist., vol. 27, 1910, p. 268. Gill, ' 

 Bull. Geol. Geogr. Surv. Terr., No. 2, ser. 2, May 14, 1875, p. 20. Osborn, Age of Mammals, 1910, p. 522. 

 » See Gregory, Bull. Amer. Mus. Nat. Hist., vol. 27, 1910, pp. 2S0-285; also Thomas (Proc. Zool. Soc. 

 London, 1890, pp. 445, 446) who remarks on dentition of Petrodromus and the other genera. 



