A New Pocket Gopher (Thomomys) and A New Spiny Pocket Mouse (Liomys) from Michoacan, Mexico
BY
E. RAYMOND HALL AND BERNARDO VILLA R.
University of Kansas Publications Museum of Natural History
Volume 1, No. 14, pp. 249-256, 6 figs. in text July 26, 1948
University of Kansas LAWRENCE 1948
UNIVERSITY OF KANSAS PUBLICATIONS, MUSEUM OF NATURAL HISTORY
Editors: E. Raymond Hall, Chairman; A. Byron Leonard, Edward H. Taylor
Volume 1, No. 14, pp. 249-256, 6 figs. in text July 26, 1948
UNIVERSITY OF KANSAS Lawrence, Kansas
PRINTED BY FERD VOILAND, JR., STATE PRINTER TOPEKA, KANSAS 1948
22-3338
A New Pocket Gopher (Thomomys) and a New Spiny Pocket Mouse (Liomys) from Michoacan, Mexico
By
E. RAYMOND HALL and BERNARDO VILLA R.
A series of 17 pocket gophers of the species _Thomomys umbrinus_ obtained in 1943 from points 3, 4 and 5 miles south of Patzcuaro proves upon comparison to be an hitherto unrecognized subspecies which is described and named as follows:
#Thomomys umbrinus pullus#, new subspecies
_Type._--Male, adult, skin and skull; No. 100151, Univ. California Mus. Vert. Zool.; 5 mi. S Patzcuaro, 7800 ft., Michoacan, Mexico; March 10, 1943; obtained by Hubert H. Hall, original No. 117.
_Range._--Known only from 3 to 5 miles south of Patzcuaro, Michoacan.
_Diagnosis._--Size small (see measurements); color black or between Cinnamon-Brown and Snuff Brown; distal half of tail whitish and all of tail whitish in one specimen; lambdoidal crests perpendicular to sagittal plane of skull; posteroventral face of tympanic bulla rugose; jugal vertical (flat surface not oblique); interpterygoid space truncate at apex with sides curved outward (see figure).
_Comparison._--From topotypes of _Thomomys umbrinus supernus_ Nelson and Goldman, _pullus_ differs as follows: More individuals wholly black (except distal half of tail); underparts lacking white; rostrum broader; braincase anteriorly slightly more expanded dorsally; lambdoidal crests perpendicular to sagittal plane rather than inclined posteromediad; interparietal broader, [Male] 5.7 (5.0-7.0) versus 4.5, and in [Female] 6.5 (5.6-7.1) rather than 4.8 (4.4-5.1); flattened middle part of jugal vertical rather than oblique; in side view, mastoid and paroccipital processes farther apart thus exposing larger surface of mastoidal bulla; incisors, in both upper and lower jaws, slightly narrower; molariform teeth smaller, interpterygoid space truncate, at apex, with sides convex mediad, rather than V-shaped; ventral face of tympanic bullae rugose in posterior half rather than smooth.