36 JJniversiiy of California Puhlications in Zoology [Vol. 21 



not be present on posterior triangle of M^. Enamel folding of M^ 

 without any especial peculiarity except that terminal loop is usually 

 very long. Outer convex surface of loop marked by slight salient angle 

 just behind point of attachment to second outer closed triangle ; inner 

 side of posterior limb of terminal loop with shallow notch or reentrant 

 angle. 



Lower molars not exhibiting any marked peculiarities, and resembl- 

 ing very closely those of calif ornicus, except that posterior transverse 

 loops are relatively wider. 



Remarks. — Elliot in his original description of this form erron 

 eously gave the type locality as San Quintin, whereas the specimen now 

 labelled as the type came from La Grulla. Later, Elliot (1907, p. 292) 

 corrected this error in a footnote. According to Elliot this race occurs 

 in the weeds and grass in the vicinity of San Quintin and follows the 

 streams up into the San Pedro Martir Mountains where it was found 

 even in the highest meadows. 



LITERATURE CITED 



Allen, J. A. 



1893. On a collection of mammals from the San Pedro Martir region of 

 Lower California, with notes on other species, particularly of the 

 genus Sitomys. Bull. Amer. Mus. Nat. Hist., 5, 181-202. 

 Bailey, V. 



1898. Descriptions of eleven new species and subspecies of voles. Proc. 



Biol. Soe. Wash., 12, 85-90. 

 1900. Eevision of American voles of the Genus Microtus. U. S. Dept. 

 Agric, Div. Biol. Surv., N. Amer. Fauna, 17, 1-88, 5 pis., 17 figs, 

 in text. 

 Baird, S. F. 



1857. Report on Zoology. I, Mammals. U. S. Pac. R. R. Expl. and Surv., 8, 

 xlviii + 757, pis. 17-60, 35 figs, in text. 

 CouES, E., and Allen, J. A. 



1877. Monographs of North American Rodentia, in Rep. U. S. Geol. Surv. 

 Territories (Washington, Govt. Printing Office), 11, i-x, 1-939, 

 1083-1091. 

 CouES, E., and Yarrow, H. C. 



1875. Report upon the collections of mammals made in portions of Nevada, 

 Utah, California, Colorado, New Mexico, and Arizona, during the 

 years 1871, 1872, 1873, and 1874, in Explorations and surveys 

 Avest 100th meridian (Washington, Govt. Printing Office), Zoology, 

 5, 35-129, 969-976. 

 Elliot, D. G. 



1898. List of mammals collected by W. W. Price and assistants, chiefly in 



California. Field Columb. Mus., Zool. ser., 1, 193-216. 

 1903a. Descriptions of apparently new species and subspecies of mammals 

 from California, Oregon, the Kenai Peninsula, Alaska, and Lower 

 California, Mexico. Ibid., 3, 153-173, 1 fig. in text. 



