Necker and Hatfield (Bull. Chicago Acad. Sci., 6:54, 1941) referred specimens from Rosiclaire, Illinois, to _S. c. gossii_. These specimens were not mentioned by Bole and Moulthrop (_op. cit._) when they named _S. c. saturatus_ although the specimens presumably would be referred to the newly-named subspecies. We have examined the pertinent specimens (Nos. 15781-15786 and 16049-16054 CNHM) and find that on the basis of dark color, long and slender skull, heavy incisors, and small cheek-teeth, they are referable to _S. c. saturatus_ Bole and Moulthrop. None, however, has a tail so short as the type of _S. c. saturatus_. For that matter, the average length of the tail of six near topotypes (5 mi. W, 2-1/2 mi. S Monticello, Piatt County, Illinois, Nos. 32037-32042 KU) exceeds that of the type (17.4 mm., range 12-20, as compared to 14 mm. for the type). Synaptomys cooperi gossii (Coues) 1877. _Arvicola (Synaptomys) gossii_ Coues, Monogr. N. Amer. Rodentia, p. 235 (published as a synonym of _Synaptomys cooperi_, but name stated to apply to Kansan specimens of which description and measurements are on p. 236), type from Neosho Falls, Woodson County, Kansas. 1897. _Synaptomys cooperi gossii_, Rhoads, Proc. Acad. Nat. Sci. Philadelphia, 49:307, June. In view of the taxonomic treatment accorded by Bole and Moulthrop (Sci. Publs. Cleveland Mus. Nat. Hist, 5:149-151, September 11, 1942) to the lemming mice of the species _Synaptomys cooperi_, as explained in the preceding account, it has seemed desirable to examine Iowan specimens of this species. Hall and Kelson examined the necessary material and made the following conclusions. An adult male from Hillsboro (168453 USBS) has the lighter color and large skull of _S. c. gossii_ to which Howell (N. Amer. Fauna, 50:19, August 5, 1927) referred the specimen. The more western specimen from Knoxville, a young male (190358 USNM), is almost exactly the same age as a male of _S. c. saturatus_ from Bascom, Indiana (143701 USNM), and is but slightly older than a male _S. c. gossii_ from Ft. Leavenworth, Kansas (91583 USBS). The upper molariform tooth-row is the same length in the specimens from Kansas and Iowa, but is longer in that from Indiana. The fact that the specimen from Knoxville closely resembles the Kansan specimen in other dimensions of the skull, which is larger than in the specimen from Indiana, gives a basis for applying the name _Synaptomys cooperi gossii_ to the specimen from Knoxville. This is the same name recently used by Fichter and Hansen (Bull. Univ. Nebraska State Mus., 3(2):2, September, 1947) for the Iowan specimens, although they seemingly applied the name without being aware of Bole and Moulthrop's earlier naming of _S. c. saturatus_ (Sci. Publs. Cleveland Mus. Nat. Hist., 5:149, September 11, 1942). Synaptomys borealis sphagnicola Preble