RODENTIA 283 



The Cooper lemming mice (Synaptomys cooperi cooperi) are 

 "chiefly herbivorous, feeding on grass stems and seeds." In captivity 

 they ate grass, clover, dandelions, plantain, narrowleaf dock and rolled 

 oats, while one ate apple, but refused carrots, radishes and celery. Of 

 8 stomachs taken in the field, 6 contained only finely ground, green 

 plant material, apparently grass, and 2 contained dark, unidentified 

 material, with a coleopterous wing covert. 2 Goss lemming mouse (S. 

 cooperi gossii) : 9 stomachs, full of vegetation, probably grass ; 5 per 

 cent of the contents of one was fungus spores and mycelial threads ; 

 another contained a beetle, with grass; in captivity they showed a 

 preference for grass and apples, but ate also lettuce, cabbage, peanut 

 butter, raisins, alfalfa, oats, clover seed and a little potato. 3 



It has been said that nothing is known of the food habits of the 

 Idaho mountain vole (Phenacomys orophilus} and Preble mountain 

 vole (P. preblei). 4 Both names are said to be synonyms of P. inter- 

 medius, the Rocky Mountain vole. 5 Coast or short-tailed phenacomys 

 (P. albipes), usually lives in dry situations and probably feeds "on a 

 variety of seeds, tender growth, and other relatively soft or brittle 

 foods for which their teeth are best suited. The long-tailed or red tree 

 mouse (P. longicaudiis) and forest tree mouse (P. silvicola) are 

 arboreal, and "their food, so far as known, consists chiefly of the fleshy 

 parts of the needles of the conifers. . . . Some tender bark also is con- 

 sumed." 6 Olympic mouse (P. intermedium olympicus) feeds upon twigs 

 of heather, beargrass, lousewort and huckleberry leaves. 7 



The familiar generic name, Evotomys Coues, 1874, applied to the 

 red-backed mice, appears to be preoccupied by Clethrionomys Tilesius, 

 i85O. 8 Gale red-backed mouse (C. gapperi galei) eats grass and seeds, 

 is confined to the mountains and is of no economic importance. 9 Loring 

 red-backed mouse (C. g. loringi) eats seeds, green vegetation and 



2 Stegeman, Notes on Synaptomys cooperi cooperi in Washtenaw County, Michi- 

 gan, Jonrn. Mammalogy, xi, 460-466, 1930. 



8 Burt, Additional notes on the life history of the Goss lemming mouse, Journ. 

 Mammalogy, ix, 212-216, 1928. 



4 Burnett, Office Colorado State Entom. Circular No. 25, p. 10, 1918. 



5 Anthony, Field book of North American mammals, p. 406, 1928. Howell, Voles 

 of the genus Phenacomys, N. Amer. Fauna, No. 48, p. 15, 1926. 



9 Howell, Voles of the genus Phenacomys, N. Amer. Fauna, No. 48, p. 2, 1926. 

 Jewett, Notes on two species of Phenacomys in Oregon, Journ. Mammalogy, I, 165- 

 168, 1920. 



7 Shaw, Alpine life of the heather vole (Phenacomys olympicus), Journ. Mam- 

 malogy, v, 12-15, 1924. 



8 Palmer, An earlier name for the genus Evotomys, Proc. Biol. Soc. Washington, 

 XLI, 87-88, 1928. 



9 Burnett, Office Colorado State Entom. Circular No. 25, p. 10, 1918. 



