Longhurst 1939 Microtus californicus Huichica Cr., 200 ft., Napa Co., Calif. Oct. 6 17 was taken at this time on a dry grassy hillside where there was a small spring. About the spring was a considerable growth of Carex and several burrows & runways could be seen. Oct. 7 E. Side Napa River, 1/2 mi. S Cuttings Wharf, Napa Co., Calif. One Microtus was trapped here on ground slightly above mean high tide level and covered with Salicornia. Oct. 21 A ? meadow mouse was taken here again under the same conditions. Traps set on a knoll slightly higher than the surrounding marsh and covered with Baccharis & dry grass, cought nothing. However, many old runs were present in the grass and it is possible that the meadow mice were found here [illegible] during the wet season.