VOL. IV.] Notes on a Collection of Mammals. 321 



mammals of the high Sierras, sharing that distinction with the 

 marmot, Ardomys flaviv enter, and the gilded chipmunk already 

 mentioned. It was especially abundant in colonies of half a 

 hundred or more in the grass}' valley at Summit Station. Other 

 colonies were seen about Mt. Tallac and Pyramid Peak, always 

 on grassy flats and gentle hillslopes. 



They are short, thick-set little rodents and have a peculiar 

 loping gait. They have the habit of sitting up on their haunches 

 when alarmed, shared by other members of the genus. This habit 

 has given them the local names of " picket-pins," " prairie dogs," 

 and " woodchucks," though the latter name is more generally 

 applied to the marmot. They often wander some distance away 

 from their burrows. I have seen a grassy meadow covered with 

 them feeding on grass seeds; when alarmed the whole company 

 would rush loping to their homes. Several shot at Summit Valley 

 had their cheek-pouches distended with the green seeds. 



A series of fifteen skins shows little color variation, and that 

 confined to the dorsal stripe and the fulvous wash of the under- 

 parts. Some young specimens, a week or two old, taken July 21 

 at Summit Station have nearly the exact color pattern of the 

 adults. Another, perhaps six weeks old, taken August 12 on 

 Mt. Tallac, is paler in color, the crown patch and dorsal stripe 

 are faint, and the under parts are bluish gray, the color extending 

 up on the sides. 



9. Spermophilus grammurus beecheyi (Rich.) California 

 Ground Squirrel. 



A single specimen was taken near Red Point. Ground squir- 

 rels are common in the Sierra Nevada up to nearly 6000 feet. 

 Higher than that they give place to the marmot, and the smaller 

 spermophiles, Spermophihcs beldingi. They frequent rocky hill- 

 sides, and though common they are shy and not nearly so con- 

 spicuous as in the valleys of California. 



10. Sciurus hudsoniiis californicus Allen. California Chick- 

 aree. 



Only three specimens were taken, two at Red Point on July 

 6 and one at Summit Station July 30. Several others were seen; 

 one along a road beside Lake Tahoe, appeared to be in the black 

 stage. My companion remarked: " That's the first black squir- 



