112 Proceedings of the Biological Society of Washington. 



Remarks. — Tliis subspecies is most closely related to oregonensis of the 

 coast region of Oregon and Washington, intermediates between the two 

 forms occurring at Sumas and Chilliwack, B. C. Intergradation with 

 fuliginosus — the form occupying the Cascades — is shown by specimens 

 from mouth of Salmon River, B. C. The present form occupies the low 

 country in the interior of British Columbia and northern Washington. 



Glaucomys sabrinus latipes subsp. nov. 



Type from Glacier, British Columbia. Adult female, No. 68,753, U. S. 

 Nat. Mus. (Biological Survey collection); collected August 13, 1894, by 

 J. Alden Loring; original number 2111. 



Characters. — Similar to G. s. fuliginosus, but larger, and upperparts 

 averaging darker and grayer; feet larger and darker colored. Compared 

 Vi'ith alpinus : Size larger; colors darker (more brownish, less drab); 

 underparts darker. 



Measurements. — Adult female (type): Total length, 359; tail vertebrae, 

 161; hind foot, 43; average of 9 adults from Coolin, Idaho, and Stanton 

 Lake, Mont. : 339,151; 40.6. Skull (of type): Greatest length, 44.2; 

 zygomatic breadth, 25.1; mastoidal breadth, 20; interorbital breadth, 

 8.3 ; length of nasals, 14; alveolar length of maxillary toothrow, 8.8. 



Remarks. — This subspecies is one of the largest of the American flying 

 squirrels, equaling yukonensis in external measurements and exceeding it 

 in size of skull. Although evidently closely related to fuliginosus, of the 

 Cascades, there is at present no evidence of intergradation with that 

 race. The present form differs widely from alpinus, which occupies the 

 eastern slopes of the Rockies in Alberta, and from the much smaller 

 bangsi of the Bitterroot and Sawtooth Ranges of Idaho and Montana. 



Glaucomys sabrinus flaviventris subsp. nov. 



Type from head of Bear Creek, Trinity County, California (altitude 

 6400 feet). Adult male. No. 13,319, Univ. of Calif., Mus. Vert. Zool.; 

 collected August 13, 1911, by Annie M. Alexander; original number 

 1775. 



Characters. — Similar in size and skull characters to O. s. lascivus, but 

 underparts and feet strongly suffused with yellow or buff; similar to 

 klamathensis , but smaller, with much smaller audital bullae; underparts 

 more yellowish and tail darker beneath. Compared with stephensi : 

 Upperparts much paler and underparts more yellowish ; skull flatter with 

 shallower braincase. 



Measurements. — Average of five adults from type locality: Total length, 

 301; tail vertebrae, 133; hind foot, 40.4; ear, 20.7. Skull (of type): 

 Greatest length, 40; zygomatic breadth, 23.4; mastoidal breadth, 17.9; 

 interorbital breadth, 7.9; length of nasals, 12.3; alveolar length of maxil- 

 lary toothrow, 8.1. 



Remarks. — This race is apparently most nearly related to lascivus of 

 the Sierra Nevada, from which it diflers widely in the color of the under- 



