On the basis of color, specimens we have examined from the Long Pines clearly are assignable to T. h. dakotensis rather than to T. h. baileyi, substantiating in part the statement of the distribution of dakotensis published by Miller and Kellogg (1955:263).
Thomomys talpoides bullatus Bailey, 1914
Northern Pocket Gopher
Specimens examined (22).—NE 1/4 sec. 22, R. 1 E, T. 23 N, 1; 7 mi. N, 2-1/2 mi. W Camp Crook, 3300 ft., 3; Camp Crook, 1; 10 mi. S, 5 mi. W Reva, 10; 10 mi. S, 4 mi. W Reva, 4; 2 mi. S, 5 mi. E Harding, 2; Crow Buttes, 1 (USNM).
The northern pocket gopher probably occurs in most areas of northwestern South Dakota where the soil is sufficiently deep for constructing burrows, but we found it commonest in the lower grassy slopes of buttes and in relatively sandy areas along some of the major streams.
A female obtained on June 20 contained two embryos that measured 3. Testes of an adult male trapped on May 18 measured 19 and those of one taken on July 6 measured 9. Juveniles were collected in both May and June.
Bailey (1915:102) referred a specimen from Crow Buttes to T. t. bullatus, but Swenk (1941:3), in the original description of T. t. pierreicolus, suggested that this same specimen "probably" was referable to the latter because he assumed it came from soils of the Pierre series. However, Baker (1952:8) included the Crow Buttes in the Hell Creek formation and, in any event, one of us (Jones) examined the specimen in question and found it clearly referable to the subspecies bullatus. Over and Churchill (1945:32) erroneously assigned pocket gophers from northwestern South Dakota to two different subspecies (bullatus and clusius), referring at least one individual from Harding County to T. t. clusius.
Fleas, Dactylopsylla ignota (Baker), were found on one individual examined. Molting adults were taken in each month from May through August.
Perognathus fasciatus fasciatus Wied-Neuwied, 1839
Olive-backed Pocket Mouse