1915.] 



THOMOMYS MONTICOLA GEOUP. 



125 



characters of pinetorum are slightly accentuated, but not sufficiently 

 for further subdivision. Specimens from Wagon Camp are to some 

 extent intermediate between pinetorum and monticola, while from 

 higher up Mount Shasta they are typical of monticola. Others from 

 half a mile west of Sisson distinctly approach mazama. Apparently 

 pinetorum is a Transition Zone form extending from Sisson south 

 through the mountains along the west side of the Sacramento Valley. 

 Specimens examined. — Total number, 54, as follows: 

 California: Grindstone Creek (head), 5; Sisson, 9; South Yolla Belly Mountain, 40. 



THOMOMYS MONTICOLA NASICUS Merriam. 

 Deschutes Pocket Gopher. 

 (PI. vm, fig. 4.) 



Thomomys nasicus Merriam, Proc. Biol. Soc. Washington, XI, 216, July 16, 1897. 



Type. — Collected at Farewell Bend, Deschutes Kiver, Crook 

 County, Oregon (west of Prineville), by Edward A. Preble, August 4, 

 1896. Type specimen in U. S. Nat. Mus., Biological Survey collec- 

 tion. 



Distribution. — West-central Oregon (east of the Cascades), from 

 Farewell Bend, Deschutes River, south to the Yamsey Momitains 

 (fig. 5). 



Characters. — Size and proportions of monticola; ears large and con- 

 spicuous; color slightly lighter and brighter; skull long and narrow, 

 with long spreading nasals. 



Color. — Summer pelage: Upperparts bright yellowish hazel with 

 plumbeous nose and ear patches; underparts rich buff; feet, most of 

 tail and chin usually whitish. Winter pelage: Duller hazel. Young, 

 paler and duller colored. 



Slcull. — Long, with narrow braincase and long rostrum ; nasals long 

 and conspicuously widened anteriorly, almost spoon-shaped in some 

 individuals, sharply emarginate at posterior tip; interparietal small 

 and transversely oval; bullae rather small. 



Measurements. — Type ( ad.) : Total length, 214; tail vertebrae, 69; 

 hind foot, 27. Slcull (of type): Basal length, 34.7; nasals, 15.4; 

 zygomatic breadth, 21.5; mastoid breadth, 16.8; alveolar length of 

 upper molar series, 7. 



Remarks. — The subspecies nasicus seems to be a well-marked form 

 of the monticola group, with skull characters placing it nearer monti- 

 cola (from which it is widely separated geographically), than to its 

 nearest neighbor, mazama, while in color it is very close to pinetorum, 

 with which it also agrees in a Transition Zone range. Its relationship 

 can best be shown by placing it as a subspecies of monticola. 



Specimens examined. — Total number, 49, as follows: 

 Oregon: Bend, 12; Deschutes River (Farewell Bend), 2; Deschutes River 

 (mouth of Davis Creek), 8; Fort Klamath, 1; Lapine, 12; Little Meadows, 1; 

 Paulina Lake, 6; Pengra, 2; Yamsey Mountains, 9. 



