From Zapus princeps idahoensis, Z. p. princeps differs in: Size larger; darker with more Ochraceous-Buff; lateral line much more distinct; underparts frequently suffused with Ochraceous-Buff rather than seldom so; skull larger as regards length of palatal bridge, length of zygomatic arch, and width of proximal part of inferior ramus of zygomatic process of maxillary; pterygoid fossae broader; medial projection on inferior ramus of zygomatic process of maxillary large instead of reduced or absent; postpalatal notch usually anterior to, or on a plane with, posterior face of last molars rather than posterior to same.

Remarks.—This subspecies retains most of its diagnostic characters in all parts of its geographic range. An individual from the type locality, Florida, Colorado, resembles Zapus princeps luteus in color, but cranially is most nearly like Z. p. princeps. A specimen from Tierra Amarilla, New Mexico, a locality 25 miles north of, and in homogeneous habitat with, El Rito, New Mexico, from which specimens of Z. p. luteus are known, shows resemblance to the latter in some cranial characters (see account of Zapus princeps luteus) but is most nearly like Z. p. princeps to which it is referred.

Animals from Medicine Wheel Ranch, 9000 ft., 28 mi. E Lovell, Wyoming, which are here referred to Z. p. princeps, show intergradation with Zapus princeps idahoensis, being similar in size of pterygoid fossae, breadth of postpalatal notch, and in size and degree of inflation of the auditory bullae, but differ in color and in other cranial characters. Specimens from 2 mi. E Shriver, 6500 ft., Montana, which lack the distinct lateral line and ventral suffusion of Ochraceous-Buff, are here referred to Z. p. idahoensis.

Specimens examined.—Total, 344, distributed as follows:

Colorado: Archuleta County: upper Navajo River, 5 (CMNH); Navajo River, 6 (CMNH). Boulder Co.: 121/2 mi. S Estes Park, 2; 3 mi. S Ward, 3; Gold Hill, 1 (USBS); 7 mi. NW Nederland’s, 2 (UM); 3 mi. E Pine Cliff, 3 (CMNH). Chaffee County: 11/2 mi. S Monarch, 10,500 ft., 2 (OKLA). Conejos Co.: Antonito, 1 (USBS); 5 mi. S and 24 mi. W Antonito, 9600 ft., 2. Costilla Co.: 7 mi. SE Russell, 9200 ft., 1 (MVZ); Fort Garland, 6 (USBS). [416] El Paso County: Minnehaha, Half Way, 5 (UM). Grand Co.: Rocky Mtn. Nat’l Park, 5 (UM). Gunnison County: Gothic, 10 (8 OKLA; 2 USBS); Major Creek, foot of Monarch Pass, 1 (OKLA). Jackson Co.: Arapahoe Pass, Rabbit Ear Mts., 1 (USBS). La Plata Co.: 7 mi. N Florida, Florida River, 7146 ft., 8 (MVZ); Florida, 6500 ft., 11 (1 FM; 9 AMNH). Larimer Co.: Elkhorn, 7000 ft., 1 (USBS); 191/2 mi. W and 21/2 mi. S Loveland, 7300 ft., 3. Mineral Co.: Wasson Ranch, Creede, 1; 3 mi. E Creede, 1; 23 mi. S and 11 mi. E Creede, 9300 ft., 5. Rio Blanco Co.: 91/2 mi. SW Pagoda Peak, 7700 ft., 5; Meeker, 1 (USBS). Rio Grande County: Rock Creek Camping Area, 1 (OKLA). Saguache Co.: Saguache Park, Cochetopa Forest, 1 (USBS); 22 mi. W Saguache, 1 (MVZ); 20 mi. S Saguache, Cochetopa Pass, 1 (USBS). San Juan County: 61/2 mi. SW Silverton, 4.

New Mexico: Rio Arriba Co.: Tierra Amarilla, 1 (USBS). Taos Co.: Hondo Canyon, 8200 ft., west slope Taos Mts., 1 (USBS); east slope Taos Mts., 8800 ft., 1 (USBS).

Wyoming: Albany County: 32 mi. N and 121/2 mi. E Laramie, 6080 ft., 1; 30 mi. N and 10 mi. E Laramie, 6760 ft., 1; 29 mi. N and 83/4 mi. E Laramie, 6420 ft., 6; 2 mi. S Browns Peak, 10,600 ft., 2; 3 mi. ESE Browns Peak, 10,000 ft., 8; 8 mi. E and 4 mi. S Laramie, 8600 ft., 2; 8 mi. E and 6 mi. S Laramie, 8500 ft., 1; 1 mi. ESE Pole Mtn., 8350 ft., 2; 11/2 mi. ESE Pole Mtn., 8200 ft., 1; 2 mi. SE Pole Mtn., 8300 ft., 3; Centennial, 8120 ft., 1. Big Horn County: Medicine Wheel Ranch, 9000 ft., 28 mi. E Lovell, 36; 12 mi. E and 2 mi. N Shell, 7500 ft., 13; 17 mi. E and 3 mi. S Shell, 9000 ft., 1; 171/2 mi. E and 41/2 mi. S Shell, 9100 ft., 6. Carbon County: Bridgers Pass, 18 mi. SW Rawlins, 7500 ft., 6; Lake Marie, Medicine Bow Nat’l Forest, 10,400 ft., 6; 14 mi. E and 6 mi. S Saratoga, 5; 10 mi. N and 10 mi. E Encampment, 8000 ft., 1; 10 mi. N and 12 mi. E Encampment, 7200 ft., 2; 10 mi. N and 14 mi. E Encampment, 8000 ft., 28; 9 mi. N and 3 mi. E Encampment, 2; 8 mi. N and 8 mi. E Encampment, 8900 ft., 1; 8 mi. N and 14 mi. E Encampment, 8400 ft., 5; 8 mi. N and 141/2 mi. E Encampment, 8100 ft., 12; 8 mi. N and 16 mi. E Encampment, 8400 ft., 6; 8 mi. N and 22 mi. E Encampment, 10,000 ft., 1; 8 mi. N and 191/2 mi. E Savery, 8800 ft., 12; 8 mi. N and 20 mi. E Savery, 8800 ft., 1; 71/2 mi. N and 18 mi. E Savery, 8400 ft., 2; 71/2 mi. N and 181/2 mi. E Savery, 8400 ft., 1; 7 mi. N and 18 mi. E Savery, 8400 ft., 2; 6 mi. N and 131/2 mi. E Savery, 8400 ft., 6; 6 mi. N and 14 mi. E Savery, 8350 ft., 6; 4 mi. N and 8 mi. E Savery, 7300 ft., 1. Converse County: 21 mi. S and 24 mi. W Douglas, 7400 ft., 6; 21 mi. S and 241/2 mi. W Douglas, 7400 ft., 3; 211/2 mi. S and 241/2 mi. W Douglas, 7600 ft., 15; 221/2 mi. S and 241/2 mi. W Douglas, 7600 ft., 1; 23 mi. S and 25 mi. W Douglas, 7800 ft., 7. Johnson County: 61/2 mi. W and 2 mi. S Buffalo, 5700 ft., 4; 51/2 mi. W and 11/2 mi. S Buffalo, 5520 ft., 3; 51/2 mi. W and 1 mi. S Buffalo, 4800 ft., 1; 1 mi. W and 4/5 mi. S Buffalo, 4800 ft., 1. Laramie County: 5 mi. W and 1 mi. N Horse Creek P. O., 3. Natrona County: 2 mi. W and 7 mi. S Casper, 6370 ft., 2. Washakie County: 9 mi. E and 5 mi. N Tensleep, 7400 ft., 2; 9 mi. E and 4 mi. N Tensleep, 7000 ft., 5.

Marginal records.—Wyoming: Medicine Wheel Ranch, 9000 ft., 28 mi. E Lovell; 21 mi. S and 24 mi. W Douglas, 7400 ft.; 5 mi. W and 1 mi. N Horse Creek P. O. Colorado: Gold Hill; Minnehaha. New Mexico: E slope Taos Mts.; Tierra Amarilla. Colorado: Florida; 61/2 mi. SW Silverton; Meeker. Wyoming: Bridgers Pass, 18 mi. W Rawlins, 7500 ft.

Zapus princeps saltator J. A. Allen

Zapus saltator J. A. Allen, Bull. Amer. Mus. Nat. Hist., 12:3-4, March 4, 1899; Preble, N. Amer. Fauna, 15:31, August 8, 1899.