New Mexico: Taos County: Twining, 10,700 ft., 3; 5 mi. S Twining, 11,400 ft., 3. Sandoval County: Goat Peak, Jemez Mountains, 1. Colfax County: 15 mi. SW Cimarron, 9000 ft., 1 (Amer. Mus. Nat. Hist.).
Additional records.--New Mexico: San Miguel Co.: Pecos Baldy, Pecos Mountain, 1 (Bailey, N. Amer. Fauna, 52:192, 1932).
Clethrionomys gapperi limitis (Bailey)
1913. Evotomys limitis Bailey, Proc. Biol. Soc. Washington, 26:133, May 21.
Type locality.--Willow Creek, a branch of the Gilita, 8500 ft., Mogollon Mountains, Catron County, New Mexico.
Range.--Known from the Mogollon, San Mateo, and Magdalena mountains of western New Mexico.
Remarks.--Bailey (Proc. Biol. Soc. Washington, 26:133, May 21, 1913) described this animal as a species and gave as general characteristics: "Size slightly larger than E. [= Clethrionomys gapperi] galei; colors duller, grayer and less buffy; skull and dentition heavier." He further characterized the skull as: "Larger, heavier and conspicuously more ridged than in galei; bullae large and especially deep; dentition heavy throughout." The type of C. limitis, as judged from the measurements given by Bailey (loc. cit.), is an exceptionally old male.
Our comparison of six adult topotypes with a series of C. g. galei from Wyoming (18 adults from 3 mi. SSE Browns Peak, 10,000 ft., Albany County, in Univ. Kansas Mus. Nat. Hist.) and with three near-topotypes of C. g. galei (3 mi. S Ward, 9000 ft., Boulder County, Colorado, in Univ. Kansas Mus. Nat. Hist.) revealed that most of the differences noted by Bailey (loc. cit.) are not evident when individuals of comparable ages are examined. Some specimens of C. g. galei exceed C. limitis in ridging of the skull and size of the teeth although conspicuous ridges and large teeth are supposedly distinctive of C. limitis. The bullae, although averaging larger in C. limitis, can be matched in size by those of specimens of C. g. galei from Wyoming.
The differences evident between C. limitis and C. g. galei are of the kind and degree that serve to separate subspecies in the species Clethrionomys gapperi and, although actual evidence of intergradation is lacking, we think that the relationships of limitis are better expressed by arranging it as a subspecies of C. gapperi than by retaining it as a full species.