Comments on
the Taxonomy and Geographic Distribution
of North American Microtines
BY
E. RAYMOND HALL and E. LENDELL COCKRUM
In preparing maps showing the geographic distribution of North American microtines, conflicting statements in the literature and identifications that, if accepted, would result in improbable geographic ranges have led to the examination of pertinent specimens with the results given below. The studies here reported upon were aided by a contract between the Office of Naval Research, Department of the Navy, and the University of Kansas (Nr 161-791), by funds provided by the University of Kansas from its Research Appropriation, and by grants for out-of-state field work from the Kansas University Endowment Association. Grateful acknowledgment is made to persons in charge of the collections at each of the following institutions for permission to use the collections under their charge: Biological Surveys Collection, United States National Museum (herein abbreviated USBS); California Museum of Vertebrate Zoology (MVZ); Chicago Natural History Museum (CNHM); University of Kansas Museum of Natural History (KU); Museum of Comparative Zoology (MCZ); United States National Museum (USNM); Department of Economic Zoology, University of Wisconsin (UWDEZ); and Zoological Museum, University of Wisconsin (UWZM).
Synaptomys cooperi saturatus Bole and Moulthrop
1942.Synaptomys cooperi saturatusBole and Moulthrop, Sci. Publs. Cleveland Mus. Nat. Hist., 5:149, September 11, type from Bloomington, McLean County, Illinois.
When Bole and Moulthrop namedSynaptomys cooperi saturatus, with type locality in Illinois, they, in effect, divided the geographic range ofSynaptomys cooperi stoneiinto two parts (see A. B. Howell, N. Amer. Fauna, 50:10 (fig. 2), August 5, 1927) since Bole and Moulthrop (op. cit.) did not assign to any subspecies the specimens from southern Wisconsin that Howell (op. cit.) had identified asS. c. stonei. Bole and Moulthrop's inclusion in their newly named subspecies of a specimen from as far west as East Columbia, Missouri, left in doubt the subspecific identity of specimens from Iowa and a specimen from Arkansas. Howell (op. cit.) had assigned this material from Iowa and Arkansas toS. c. gossii.
Howell recognized that the one individual (168266 USBS) from Lake City, Arkansas, was too young to be identified to subspecies with certainty and assigned the specimen toS. c. gossii"upon geographical grounds" (op. cit.:19). Keith R. Kelson and one of us (Hall) compared this specimen with pertinent materials. As a result of this comparison we refer the specimen, on the same grounds employed by Ho