Additionally, we took lactating females on July 6, July 7, and August 7, and two individuals with recent placental scars on August 5. Twenty adult males collected in the period July 6 to 18 had testes that averaged 9.3 (6-11.5), whereas those of two taken on August 4 and 5 measured 10 and 12, respectively. Young animals in juvenal pelage were captured in each month, May through August, the earliest being taken on May 20. The first female young of the year that was found carrying embryos was trapped on June 16. Molt from winter to summer pelage is evident on some specimens taken as early as the latter part of May, but most individuals from that period and from the first part of June still retained winter pelage. By the last half of June, some mice had completed (or nearly so) the seasonal molt, but many retained at least some worn pelage of winter into the first week of July. Two distinctive maturational pelages are seen in our material--juvenal and post-juvenal or subadult, which generally resembles adult pelage (of season) in texture but is duller of color. Collins (1918) for _P. maniculatus_, Hoffmeister (1951) for _P. truei_, and Brown (1963) for _P. boylii_, among others, have described maturational pelages and sequence of maturational molts similar to those observed in our specimens. Deer mice from Harding County clearly are referable to _P. m. nebrascensis_ (rather than to the smaller and paler _P. m. luteus_, which occurs to the east and southeast), even though adults average somewhat paler than adults of typical populations of that subspecies. A tick of the _Ixodes ochotonae-angustus_ complex was obtained from one specimen. ~Onychomys leucogaster missouriensis~ (Audubon and Bachman, 1851) Northern Grasshopper Mouse _Specimens examined_ (4).--NE 1/4 sec. 22, R. 1 E, T. 22 N, 2; 2 mi. N, 5 mi. W Ludlow, 1; 14 mi. S, 4 mi. W Reva, 1. We found the grasshopper mouse uncommon in Harding County. All four of the mice listed as examined were trapped in areas supporting sage and short grasses, with relatively little ground cover. Three of our four specimens are immature--two males collected on May 31 (testes 10, 12) and a female taken on June 25. An adult male trapped on June 18 was in winter pelage, but molt was underway on the crown, between the ears, and over the upper back and shoulders. ~Neotoma cinerea rupicola~ J. A. Allen, 1894 Bushy-tailed Wood Rat _Specimens examined_ (8).--2 mi. N, 5 mi. W Ludlow, 5; 12 mi. N Buffalo, 1 (USNM); 7 mi. N, 2-1/2 mi. W Camp Crook, 3300 ft., 1; 2 mi. S, 5 mi. E Harding, 1.