Distribution in Tamaulipas.—Known only from Aserradero del Infernillo (Goodwin, 1954:9 and 1961:9).
Geomys personatus personatus True
Texas Pocket Gopher
1889. Geomys personatus True, Proc. U. S. Nat. Mus., 11:159 for 1888, January 5, type from Padre Island, Cameron County, Texas.
Distribution in Tamaulipas.—Known only from the barrier beach in northeastern part of state.
The specimens examined are referred, tentatively, to Geomys personatus personatus on geographic grounds. They average smaller in all measurements than personatus (but are larger than G. p. megapotamus), do not have the sagittal crest that usually is present in personatus, and the shape of the pterygoid bones is distinctive. In personatus and megapotamus the ventral border of the pterygoids (in lateral view) is convex instead of nearly straight as in specimens from the barrier beach. The specimens recorded here are all that are known of G. personatus (see account of G. tropicalis) from México.
Measurements.—Average and extreme external measurements of five females from 73 miles south of Washington Beach are as follows: 266.8 (263-271); 94.8 (91-98); 34 (33-35). Cranial measurements of two males (89038, 89032) and average and extremes of five females are respectively: basal length, 49.1, 46.6, 45.9 (44.2-46.8); basilar length, 42.9, 40.0, 39.8 (38.0-40.8); zygomatic breadth, 29.6, 28.3, 28.0 (25.7-29.9); squamosal breadth, 27.8, 25.9, 26.2 (23.8-25.4); interorbital constriction, 7.4, 6.9, 7.3 (6.7-7.8); alveolar length of maxillary tooth-row, 10.3, 9.2, 9.4 (9.1-9.7).
Records of occurrence.—Specimens examined, 17: 35 mi. SSE Matamoros, 8; 33 mi. S Washington Beach, 1; 73 mi. S Washington Beach, 8.
Additional record: 4 mi. S Washington Beach (Selander et al., 1962:335—possibly fragmentary skeletal remains never catalogued in any research collection).