1918] Kellogg: Microtus calif ornicus Group of Meadow Mice 27 



Total number of specimens examined, 33, from the following locali- 

 ties in California. Kern County : Bakersfield, 1 ; Bodfish, 5 ; Fay 

 Creek (6 miles N Weldon), 8; Onyx, 10; Weldon, 1; Fort Tejon, 7. 

 Tulare County: Taylor Meadow, 1. 



Specimens froni Fort Tejon are apparently intergrades between 

 typical kernensis and the southern California form, neglectus. 



Diagnosis. — Size large (hind foot, 21 to 25 mm., condylobasal 

 length of skull in largest individuals, 31.4 mm.) ; second upper molar 

 with open posterior lobe ; skull long, not angular, and relatively 

 smooth in adults (ratio of zygomatic breadth to condylobasal length 

 about 57%) ; interorbital region not developing a single median ridge 

 with age, but always with definite sulcus between ridges. 



Color. — Mass effect on dorsal area tawny-olive, darkened by the 

 dark overhairs. In fresh pelage : Upperparts with light terminal 

 portions of hairs varying from clay to cinnamon-buft', very incon- 

 spicuously lined with long, dark, warm sepia overhairs. Basal por- 

 tion of fur everywhere blackish plumbeous. Sides lighter than upper- 

 parts, with light terminal portions of hairs approaching pinkish buff. 

 There is no true line of demarcation between dorsal area and sides, 

 but transition to gray of underparts is rather abrupt. Rump not 

 decidedly brighter than dorsal area. Underparts pallid mouse gray 

 or white, sometimes irregularly darkened by the plumbeous bases 

 of the hairs showing through. Anal area nearly pure white. Ter- 

 minal portions of whiskers much lighter than basal portions. Nose 

 normally not conspicuously darker than area in front of eyes. Ears 

 moderate in size, not concealed by fur, with anterior border darkened 

 by plumbeous hair bases. Tail distinctly bicolor, usually warm sepia 

 above and whitish below, though when tail is scantily haired the 

 yellowish scales show through. Hands and feet covered with pale 

 drab gray hairs. In worn pelage : Duller, with greater effect of dark 

 overhairs. 



Skull. — Skull characterized by relatively smooth brain-case, short 

 rostrum, and small bullae. Dorsal profile rather evenly convex, with 

 slight interorbital depression. Occiput rounded but concealing for 

 the most part the condyles when skull is viewed from above. 



Brain-case subovate, its sides rounded and truncated anteriorly 

 by winglike postorbital tuberosities which produce a marked break 

 in contour of skull. Longitudinal ridges along outer edges of parietals, 

 if present, but poorly developed. Interorbital ridges variable in ap- 

 pearance, separated by a shallow sulcus of varying width. Inter- 

 parietal subrectangular, its posterior border nearly straight and at the 

 most but little convex, with lateral extremities squarely truncate. The 

 anteroposterior diameter exclusive of median projection more than 

 one-third greatest transverse diameter. Posterior margin of frontals, 

 convex, truncate or emarginate. 



Rostral region shorter than that in either mariposae or mohavensis. 

 Least depth behind incisors greater than width in same region. 

 Proximal depth of rostrum approximately equal to its median length. 

 Nasals long, narrow, expanded slightly anterior to the middle, but not 

 attaining the pronounced spatulate shape as in mariposae and moha- 

 vensis. Posterior termination of nasals truncate or emarginate, not 

 extending beyond incisors and exceeded posteriorly by ascending 



