Vol. XXVIII, pp. 109-114 May 27, 1915 



PROCEEDINGS 



OF THE 



BIOLOGICAL SOCIETY OF WASHINGTON 



DESCRIPTIONS OF A NEW GENUS AND SEVEN NEW 

 RACES OF FLYING SQUIRRELS. 



BY ARTHUR H. HOWELL. 



A study of the American flying squirrels has led to the dis- 

 covery of a number of unrecognized forms, preliminary descrip- 

 tions of which are presented herewith. The subgenus Glaucomys 

 Thomas,* is believed to be of generic rank and the name is 

 therefore used for all the American species. The large Hima- 

 layan species, Sciuropterus fimbriatus Gray, referred by Thomas 

 to Glaucomys, is here made the type of a new genus. Sciuropterus 

 F. Cuvier, 1825, as has been shown by Miller, t is a synonym 

 of Pteromys G, Cuvier, 1800t; the latter name, in my opinion, 

 should be restricted to the small Palaearctic species — volans,% 

 huchneri, and related forms. 



Eoglaucomys genus nov. 



Type, Sciuroptera fimbriata Gray (= Sciuropterus fimbriatus aiict.). 



Characters. — Skull essentially similar in general features to that of 

 Glaucomys; postorbital processes longer and more strongly decurved; in- 

 terparietal with antero-posterior diameter much greater than in Glauco- 

 mys — about two-thirds of the transverse diameter ; molariform teeth much 

 as in Glaucomys, with comparatively simple structure, but tvith crown of 

 pm^ divided into tivo cusps by a distinct sulcus (partially worn teeth 



•Ann. & Mag. Nat. Hist., (ser. 8) 1, 1908, p 5 (type Mus volans Linn.). 



t Proc. Biol. Soc. Wash.. XXVII, 1914, p. 216. 



X Pteromys G. Cuvier, Lemons Anat. Conip., I, 1800— Type, Sciurus volans Linn. = 

 Pteromys rtissicus auct. 



$ Linnaeus (Syst. Nat. ed. 10, 1758) named the European flying squirrel Sciurus volans 

 and the American species Mus volans; the names are not homonyms, therefore, and in 

 recognizing the two animals as generically distinct, it will be necessary to use the name 

 Pteromys volans (= P. russicus of Tiedemann and later authors) for the Russian animal, 

 retaining Glaucomys volans for the small species of eastern North America. 



19— Proc. Biol. Soc. Wash., Vol. XXVIII, 1915. (109) 



