_Measurements._--Mean and extreme measurements in millimeters of 6 males and 5 females from 3 mi. NW Higbee and the vicinity of Two Buttes are, respectively, as follows: total length, 357 (345-368), 345 (310-379); length of tail, 147 (140-158), 159 (138-178); length of hind foot, 35 (32-38), 36.4 (35-38); length of ear, from notch, 25.5 (25-26), 25.7 (25-27); weight (in grams), 234 (213-253), 206 (161-246); basilar length, 37.9 (36.8-38.9), 36.2 (34.5-38.6); length of nasals, 19.0 (18.2-20.0), 17.9 (16.4-19.6); zygomatic breadth, 23.9 (23.0-24.5), 23.3 (22.3-24.0); interorbital breadth, 5.3 (4.9-5.6), 5.1 (5.0-5.3); breadth of rostrum, 7.2 (6.8-7.7), 6.8 (6.7-6.9); diastema, 12.8 (12.3-13.3), 12.2 (11.1-13.7); alveolar length of maxillary tooth-row, 9.5 (9.2-9.8), 9.4 (9.0-9.7); length of incisive foramina, 9.7 (9.2-10.2), 9.2 (8.6-10.2); length of palatal bridge, 8.8 (8.4-9.2), 8.5 (8.0-8.9). _Measurements of the type._--Total length, 348; length of tail, 143; length of hind foot, 35; length of ear, from notch, 25; weight (in grams), 230; basilar length, 38.1; length of nasals, 18.8; zygomatic breadth, 24.2; interorbital constriction, 5.5; breadth of rostrum, 7.2; diastema, 13.0; alveolar length of maxillary tooth-row, 9.2; length of incisive foramina, 9.7; length of palatal bridge, 8.9. _Remarks._--The large size and distinctive cranial characters of _N. m. scopulorum_ are fairly constant in the northeastern part of its range, but there is a wide range of variation in color. The only two skins from the type locality differ markedly in color. Both specimens (the type and KU 37138, adult male) were collected on 16 May 1950 and are in moderately worn pelage. The upper parts of the holotype are much more yellowish than in KU 37138, and are even lighter buff than adults in unworn pelage from Two Buttes. The underparts of the holotype are more extensively white than in almost any other specimen seen of _Neotoma mexicana_. The basal gray coloration, where it is present along the sides of the venter, forms only a narrow intermediate color band extending not more than one third the length of the hairs. An extensive area of the throat, breast, axillae, median belly, and inguinal region is covered by hairs pure white to the skin. The dark line around the mouth is present, as usual for the species. The upper parts of KU 37138 are like those of the adult in worn pelage from Two Buttes peak, described above; the underparts have only small patches of pure white fur on the throat and inguinal region, being elsewhere gray at the base of the fur, as is usual for the species.