Type.—Obtained in southern British Columbia (probably near Lake Osoyoos) by J. K. Lord, probably in 1860.
Racial characters.—Size large; color of upper parts buffy-olive, washed with blackish; sides buff-olive; facial markings absent or, if present, indistinct and pale olive; tail blackish above, olive below.
Measurements.—Twenty-nine males and 10 females average, respectively: total length 175, 171; length of tail 93, 89; hind foot 23.4, 22.9; ear 5.3, 5.1.
Distribution.—Okanogan Valley and the Columbian Plateau, except for the southwestern part. Marginal localities are: Vantage, Grant County (W. W. D.), 10 mi. S. Moses Lake (W. W. D.), Washtucna (M. V. Z.) and Pullman (M. V. Z.).
Remarks.—There are constant differences between Perognathus parvus parvus and Perognathus parvus lordi. The latter is larger, darker, and differs slightly in average cranial measurements. The Snake River, the Columbia River, and the Wenatchee Mountains separate the geographic ranges of the two subspecies and prevent intergradation between them. Nevertheless their close similarity and probable common origin indicate that both belong to one species, namely parvus.
Perognathus parvus columbianus [Merriam]
Perognathus columbianus [Merriam], Proc. Acad. Nat. Sci. Philadelphia, p. 263, September 27, 1894.
Perognathus lordi columbianus, [Osgood], N. Amer. Fauna, 18:40, September 20, 1900.
Type.—Obtained at Pasco, Franklin County, Washington, by Clark P. Streator on May 9, 1891; type in United States National Museum.
Racial characters.—Size and color as in lordi but skull considerably wider in mastoid region.