SCIURID^— SPERMOPOILUS GRAMMURUS AND VARIETIES. 831 



which is, in fact, its nearest affme, though differing greatly from it in color 

 and in the size of the ears and the character of the tail. 



The varieties of grammurus differ from each other somewhat in size, 

 but mainly in coloration. The difference in size between vars. grammurus 

 and beecheyi, as indicated by the measurements of the skulls of the two forms, 

 is perhaps in part due to locality ; all the grammurus specimens being from 

 the Rocky Mountains of Colorado and New Mexico, while the beecheyi speci- 

 mens come almost wholly from Fort Tejon, Lower California. The difference 

 in size between vars. beecheyi and douglassi seems susceptible of a similar 

 explanation, the larger (douglassi) being northern. Between beecheyi and 

 douglassi, the intergradation is most thorough, while beecheyi passes gradually 

 into grammurus. Specimens from the most distant localities are sometimes 

 quite indistinguishable, as in the case of No. 9568, from Golden City, Colo., 

 and No. 3618, from Fort Tejon, Cal., between which there is no essential 

 difference in coloration. In var. beecheyi, the ear appears to be generally a 

 little higher, narrower, and more pointed than in var. grammurus. 



Synonymy and nomenclature. — Var. grammurus was first described by 

 Mr. Say in 1823, from specimens obtained on the headwaters of the Arkan- 

 sas, now within the State of Colorado. Its first synonym is the Spennophilus 

 couchi, described by Professor Baird, in 1855, from black specimens collected 

 by Lieut. D. N. Couch in the provinces of New Leon and Tamaulipas, near 

 the United States and Mexican boundary-line. It is distinguishable only by 

 its color from var. grammurus, of which it is merely a melanistic phase. Its 

 next and only other synonym is the Spermophilus buckleyi, described by Dr. 

 Slack in 1861, from a specimen from the Pecos River, also based on speci- 

 mens in melanistic condition, in which the anterior half of the dorsal surface 

 is black, and the hairs elsewhere have much more black than usual at the 

 tips. Another specimen, from near the same locality, also shows a melanistic 

 tendency. There are also in the collection melanistic specimens of var. beecheyi 

 from Fort Tejon. As stated by Professor Baird, the Sciurus grammurus of 

 Say was wholly lost sight of for many years, until it was rediscovered by the 

 Government expeditions sent out about 1853-56 ; it is not alluded to by 

 Audubon and Bachman in their general work on the Quadrupeds of North 

 America; and it is referred to by Dr. Giebel as late as 1855 as a doubtful or 

 indeterminable species. 



Vars. beecheyi and douglassi were both described by Dr. Richardson in 



