830 MONOGRAPHS OP NORTH AMERICAN RODENTIA. 



gray shoulder-patches being darker, — Muck instead of brown. This space 

 varies from dark brown to black, and is either concoloror mixed more or less 

 with touches of white. It extends generally from the nape to the middle of 

 the hack, hul is variable in respect to both length and width. The passage 

 into var. beecheyi is by almost imperceptible steps. 



The specimen (No. 1180) representing the most extreme phase of dif- 

 ferentiation from the beecheyi form is from Klamath Lake, Oreg. Another 

 (piite similar (No. 5897) is marked as probably from Fort Crook, Cal. ; it is, 

 however, somewhat browner. No. 536, from Fort Crook, is much like the 

 last; though marked "beecheyi", it seems to belong to the douglassi series. 

 Another specimen (No. 3G16), from Fort Tejon, is but a step removed from 

 the typical douglassi phase. Some of the numerous Fort Tejon specimens 

 (var. beecheyi) have the middle of the back uniformly dark brown, with a 

 very few touches of white ; while the pattern of markings is typically like 

 that of beecheyi, the mesial band, though brown rather than black, is darker 

 than any other portion of the dorsal region. In both vars. beecheyi and doug- 

 lassi, the scapular mantle is often divided by merely a very narrow line, and 

 at other times by a broad band. The shoulder-patches also vary from very 

 broad silvery-white areas, with slight touches of black, to those that are much 

 narrower, and with a much greater admixture of black. No. 9318, from Vir- 

 ginia City, Nev., has the shoulder-patches nearly obsolete, as in var. gravi- 

 nturus, to which this specimen should perhaps be referred. It is, however, 

 very like No. 3618 from Fort Tejon. The intergradation between vars. 

 beecheyi. and douglassi is most thorough. 



Habitat. — Northern California, northward to Washington Territory. 



Three skulls of var. douglassi give an average length of about 2.30, being 

 somewhat larger than var. beecheyi and rather smaller than var. grammurus. 

 The skulls of douglassi afford no characters by which they can be separated 

 from those of the other varieties. 



GENERAL REMARKS RESPECTING SPERMOPHILUS GRAMMURUS AND ITS VARIETIES. 



Distinctive characters and affinities. — Spermophilus grammurus is 

 widely distinct from all other members of the genus. It is at once recognizable 

 by its long, full, bushy tail, large pointed ears, and its general Sciurine form. 

 It also differs greatly from all the others in color and size, except S. empetra, 



