280 



BULLETIK" 56, tTNITED STATES NATIONAL MUSEUM. 



where new hair is coming in, or where the young in nursing removed 

 the walnut juice, the hair is pure white. At the first molt after the 

 walnut-eating season is past the pelage becomes pure white. Indi- 

 viduals having the pelage discolored invariably have their palms 

 stained also', while those living away from walnut trees have white 

 bellies and clean hands. Those killed in August at the summit of 

 the Huachuca Mountains, at an altitude of 9,000 feet, and far above 

 the limit of walnut trees, always had white bellies, while those shot 

 at the same season in canyons wooded with walnut almost invariablj'' 

 had the belly discolored. 



Habits and local distribiition. — We found this squirrel abundant 

 in the Huachuca Mountains, but failed to discover it in any of the 

 neighboring mountains. In the Huachucas it was found from near 

 the lower timber' line to the actual summit (2,887 meters or 9,472 

 feet). As remarked by Mr. Nelson, a specimen from the east side 

 of the Santa Catalina Mountains, Arizona, between the type locali- 

 ties of arisonensis and huachuca, is intermediate between the two 

 forms. For this interesting specimen I am indebted to Mr. Herbert 

 Brown. As long ago as September 26, 1884, I learned of the pres- 

 ence of this squirrel in the Huachuca Mountains, from Lieut. Harry 

 C. Benson, who found it within 2 miles of Fort Huachuca. In July 

 and August, 1893, it appeared to be feeding chiefly upon black 

 walnuts, and was usually found near streams. 



Measurements of 20 specimens of Sciurus arisonensis huachuca. 



