1915.3 



THOMOMYS DOUGLASI GEOUP. 



117 



a white spot on breast in all of the topotypes; nose gray; feet and 

 tail soiled whitish. Winter and young pelages not seen. 



STcull. — Long and narrow, somewhat of the monticola type, but 

 with heavier rostrum, wider interorbital constriction, and with 

 zygomatic arches conspicuously widest at anterior angle; inter- 

 parietal very small and transversely oval; bullae smaU and narrow; 

 basioccipital triangular; pterygoids low and U-shaped. 



Measurements. — Average of 3 topotypes ( c? ad.) : Total length, 

 215; tail vertebrse, 64; hind foot, 30. Average of 4 females: 200, 58, 

 28.6. SlcuU (of topotype, ^ ad.):^ Basal length, 36; nasals, 14; zygo- 

 matic breadth, 22.5; interorbital breadth, 7; mastoid breath, 19; 

 alveolar length of upper molar series, 7.6. 



Remarks. — The weU-developed ears, number and position of 

 mammae, general tone of coloration, and long narrow skull at first 

 suggest douglasi as the type of the monticola group, but the heavier 

 claws, more rounded ear tips, heavier rostrum, and wider interorbital 

 region seem to be group characters shared only by douglasi, oregonus, 

 yelmensis, melanops, limosus, and niger. This group of isolated 

 forms may somewhere connect with mazama, which seems to be its 

 nearest relative and neighbor, but for convenience it may be 

 termed the douglasi group. With the smaller-eared, slenderer-clawed 

 fuscus group, it seems less closely connected. From quadratus 

 and columhianus it differs widely in external as weU as cranial 

 characters. 



Specimens examined. — Total number, 7, as follows: 

 Washington: Vancouver (6 or 7 miles northeast, at Fourth Plain), 7.^ 



THOMOMYS DOUGLASI OREGONUS Merriam. 

 Oregon Pocket Gopher. 

 (PI. vm, fig. 8.) 



Thomomys douglasi oregonusMeTTiam, Proc. Biol. Soc. Washington, XIV, 115, July 19, 

 1901. 



Type. — Collected at Ely, near Oregon City, Oregon (exact locahty in 

 Ely's orchard), by Clark P. Streator, October 24, 1893. Type speci- 

 men in U. S. Nat. Mus.^ Biological Survey collection. 



Distrihution. — Known only from type locahty (fig. 5). 



CJiaracters. — Size about as in douglasi; ears smaller, but of the same 

 rounded form; color brighter hazel; skull relatively shorter and 

 wider, with distinctly triangular interparietal; mammae in 4 pairs, 

 inguinal 2-2, pectoral 2-2. 



Color. — October specimens in thin summer pelage: Upperparts 

 clear bright hazel, with dusky nose and cheeks and blackish ear patch; 



No. 65929, V. S. Nat. Mus. 



2CoUected by Clark P. Streator, June 15-16, 1894. 



