A New Pocket Gopher (Thomomys) and A New
Spiny Pocket Mouse (Liomys) from
Michoacán, 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 Michoacán, Mexico
By
E. RAYMOND HALL and BERNARDO VILLA R.
A series of 17 pocket gophers of the species Thomomys umbrinusobtained in 1943 from points 3, 4 and 5 miles south of Pátzcuaroproves upon comparison to be an hitherto unrecognized subspecieswhich 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 Pátzcuaro, 7800 ft., Michoacán, Mexico; March 10, 1943; obtainedby Hubert H. Hall, original No. 117.
Range.—Known only from 3 to 5 miles south of Pátzcuaro, Michoacán.
Diagnosis.—Size small (see measurements); color black or between Cinnamon-Brownand Snuff Brown; distal half of tail whitish and all of tail whitishin one specimen; lambdoidal crests perpendicular to sagittal plane of skull;posteroventral face of tympanic bulla rugose; jugal vertical (flat surface notoblique); interpterygoid space truncate at apex with sides curved outward(see figure).
Comparison.—From topotypes of Thomomys umbrinus supernus Nelson andGoldman, pullus differs as follows: More individuals wholly black (exceptdistal half of tail); underparts lacking white; rostrum broader; braincase anteriorlyslightly more expanded dorsally; lambdoidal crests perpendicular tosagittal plane rather than inclined posteromediad; interparietal broader, ♂ 5.7(5.0-7.0) versus 4.5, and in ♀ 6.5 (5.6-7.1) rather than 4.8 (4.4-5.1); flattenedmiddle part of jugal vertical rather than oblique; in side view, mastoid andparoccipital processes farther apart thus exposing larger surface of mastoidalbulla; incisors, in both upper and lower jaws, slightly narrower; molariformteeth smaller, interpterygoid space truncate, at apex, with sides convex mediad,rather than V-shaped; ventral face of tympanic bullae rugose in posterior halfrather than smooth.
Figs. 1-3. Three views of the skull of the type specimen of Thomomysumbrinus pullus. × 1.Remarks.—Among named subspecies of Thomomys umbrinus,T. u. pullus most closely resembles T. u. supernus, the subspeciesnext adjacent to the northward. Therefore, the r