222 
THE MAMMALS OF MOUNT MAZAMA. 
Long-tailed Vole. Microtus mordax^ Merriam. 
This long-tailed vole is a mountain or Boreal animal and is 
rather common on the steep west slope of Castle Crest on the rim of 
Crater Lake, where it occurs both in springy places and in drier sit- 
uations. Like the large vole it makes runways and holes, and cuts 
much grass and other small plants. It was obtained by Mr. Preble 
at Diamond and Paulina Lakes, and by Mr. Bailey and myselt on 
West Sink Creek and the upper Des Chutes river. On Mount 
Mazama it follows the cold streams down to Fort Klamath where it 
is common in the thick grass and bushes bordering Wood river and 
Fort Creek. 
Common Vole. Microtus caliiornicus, Peale. 
Klamath Indian name, Gli-wa. 
The California Vole seems to be restricted to the Transition 
Zone and consequently does not occur on the mountain. It is 
common at Fort Klamath where it Vas found chiefly in the hay 
fields. 
Giant Vole. Microtus (Arvicola) arvicoloides, (Rhoads). 
Klamath Indian name, GH wa. 
This, the largest of the Voles of Mount Mazama, is common in 
a variety of places within the Hudsonian Zone, but always in damp 
or moist situations. Numerous specimens were obtained at Crater 
Lake and along the upper part of Anna Creek, near Pole Creek. 
At the latter locality two were caught in steel traps set in runways 
of the Sewellel (Aplodontia). This species is partly aquatic and is 
abundant along little spring streams where it makes large runways 
of its own in very wet places, and cuts much grass and many 
succulent water plants, leaving the cuttings scattered about its run- 
ways. It has large side glands which secrete a musky odor. Many 
young were caught ranging from a quarter to three-quarters grown. 
One of the old females contained 7 embryos. 
Baird's Vole. Microtus (Chilotus) bairdi, Merriam. 
This new species was caught by Mr. Bailey at the north base of 
Glacier Peak, on the rim of Crater Lake, where it was living in 
burrows in open grassy places on the pumice sand. It is interesting 
as being the second species described of the subgenus Chilotus — a 
