The Squirrels of Eastern North America. 163 



cheeks gray ; a black orbital ring ; ears sparsely haired, dusky ; under 

 parts dirty white, the hairs plumbeous at base ; under side of tail yel 

 lowish white washed with drab and sooty. Summer pelage : whole upper 

 parts uniform sooty drab. 



Cranial characters. Skull large; audital bullse small and flat (for the 

 genus) ; the bone dense ; nasals slightly turned up at end pug-nosed ; 

 all the teeth, including penultimate upper premolar, large. Size of an 

 average adult skull: basilar length, 32.4; occipitonasal length, 38.4; 

 zygomatic breadth, 22.8; greatest height of cranium above palate, 12.4; 

 greatest length of single half of mandible, 23.4. 



Size. Average measurements of seven adult specimens from Greenville, 

 Maine: total length, 278.6; tail vertebra, 130.4; hind foot, 37.6. 



General remarks. Dr. Allen, in 1874, relegated this fine species to sub- 

 specific rank, calling it a variety of Sciuropterus volans (alias volucella], and 

 followed the same arrangement in 1877 in his Monograph of the Sciuridse, 

 where he makes the statement "Grades insensibly into var. volucella." 

 How or where Dr. Allen found intergrades I am at a loss to know. In 

 reality Sciuropterus sabrinus and S. volans are two distinct species and never 

 intergrade. Wherever their geographic ranges meet they occur together, 

 often in the same wood, each species keeping distinct and retaining its 

 characters as well as where far removed from contact with the other. 

 S. sabrinus meets and overlaps the range of S. volans for a short distance, 

 wherever the Canadian and Transition faunas meet. Dr. C. Hart Merriam 

 found both species breeding in the Adirondack region of New York, and 

 in his interesting accounts of the habits of these squirrels clearly shows 

 the two to be specifically distinct, although he retained the varietal names 

 of Allen. In the same wood lot at Peterboro, N. Y., Mr. Gerrit S. Mil 

 ler, Jr., took on November 22, 1894, a fine example of S. volans, and on 

 December 28, 1895, a pair of S. sabrinus. He has kindly lent me the 

 specimens, which are now before me. I have both species from Han 

 cock, N. H., but there volans is apparently the more common. I have 

 yet to see a specimen that is in any way intermediate between S. sabrinus 

 and S. volans, and if one did turn up it would be safe to consider it a 

 natural hybrid and not an intergrade. 

 Specimens examined. Total number, 24, from the following localities : 



Nova Scotia: Annapolis, 3; Digby, 1. 



Ontario: Nepigon, 1. 



Maine : Greenville, 8 ; Bucksport, 2. 



New Hampshire : Hancock, 1. 



New York : Peterboro, 2. 



Arctic America : Eed River, 2; Fort Resolution, 1 ; Big Island, 1 ; 

 Moose Factory, 2. 



Sciuropterus silus sp. nov. Alleghany Mountain Flying Squirrel. 



Type from top of Katis Mountain, White Sulphur Springs, W. Va., at an 

 altitude of 3,200 feet. No. 4931, tf adult, collection of E. A. and O. Bangs. 

 Collected by Thaddeus Surber September 2, 1895. Total length, 214 ; tail 

 vertebrae, 92 ; hind foot, 28. 



