Longhurst 1939 Perognathus parvus July 19 Paterson, 250 ft., Benton Co., Wash. found in cheek pouches. The mice from the island were on the average heavier than those from the adjacent mainland. July 23 Snake R., 350 ft., 1 mi. N Burbank, Walla Co., Wash Perognathus were collected in several places about here: 5 and 8 mi ENE Pasco, Franklin Co.; 2 mi SSE Burbank, Walla Walla Co. and 4 mi NW Richland, Benton Co. At all localities they were abundant especially ENE Pasco where they occurred in great numbers. They were probably least about at Richland but a better locality could probably have been found near there. In all cases they were found in sandy sagebrush covered soil and in the vicinity of sand dunes. A few from each place were also found to have Bromegrass seeds in their cheek pouches. All the Perognathus collected from all localities had moult lines, but those from Crooked R. and Weed showed them least and appeared to be more nearly in winter? Pelage.