MEADOW MICE 133 



Suggests commencement of breeding activity at some time in late April 

 or early May. When we first came into the range of the species on June 10 

 many of the females contained embryos ; this condition obtained throughout 

 June and July. The latest records of breeding females are for August 30 

 at Vogelsang Lake and September 10 at Walker Lake. Continued trapping 

 within the range of the species during October failed to reveal further 

 breeding ; hence the warmer six months of the year seem to encompass the 

 breeding period. The numbers of embryos ranged from 3 to 7, the average 

 for 21 cases being close to 5 in a litter. It may well be that females bear 

 more than one litter a year, as is known to be the case with other meadow 

 mice. A few females gave evidence of having bred before attaining the 

 dimensions of a fully grown animal. 



Short-tailed Meadow Mouse. Lagurus curtatus (Cope) 



Field characters.- — Body size about twice that of House Mouse; tail very short, less 

 than 1/4 head and body; pelage dense and lax. Head and body 4i/4 inches (110 mm.), 

 tail 1 inch (25 mm.), hind foot % inch (19 mm.), ear from crown about % inch (11 

 mm.); weight slightly over 1 ounce (32.5 grams) [one individual only]. Pelage light 

 ashy gray above; paler, almost white, on under surface. 



Occurrence. — Recorded only at Mono Mills, east of Sierra Nevada. Lives on and 

 in ground beneath sagebrush. 



The Short-tailed Meadow Mouse was collected in only one locality, the 

 extreme eastern end of the Yosemite section, at Mono Mills, south of Mono 

 Lake. Two female individuals, an adult and a half-grown youngster, 

 presumably representatives of one family, were obtained, June 7 and 10, 

 1916. Both were taken in one location, under sagebrush on the edge of a 

 dry gully. The stomach contents of the adult consisted solely of chewed-up 

 leaves of sagebrush. There was neither water nor meadow nor grassland 

 anywhere near the place where the two animals were caught. This species 

 appears not to require such surroundings, but to be adapted to life in an 

 arid situation. It is distributed throughout a considerable portion of the 

 Great Basin sagebrush countrv. 



'Vo^ 



Mountain Lemming Mouse. Phenacomys orophilus Merriam 



Field characters. — Body size about twice that of House Mouse; tail short, decidedly 

 less than one-half head and body (fig. 20c) ; hind foot under % inch. Head and body 

 about 4 inches (98-108 mm.), tail 1% to 11/2 inches (28-40 mm.), hind foot % inch 

 (18-19 mm.), ear from crown about % inch (14-16.5 mm.); weight % to 1 ounce 

 (21.0-30.2 grams). Coloration ashy, brown-tinged on back, whitish on under surface; 

 feet and tail pale ashy. 



Occurrence. — Sparse resident chiefly in Hudsonian Zone. Recorded at Ten Lakes 

 (9200 feet altitude). Glen Aulin (7700 feet), head of Lyell Caiion (at 9750 feet) and 

 near Vogelsang Lake (10,100 feet) ; single individuals taken in each place. Lives about 

 patches of Sierran heather and under other plants characteristic of the same altitudes. 

 Solitary. 



