1856. The quadrupeds of Illinois. Part I, Rep. Commiss. Patents: Agriculture, pp. 52-110, 1857. LANTZ, D. E. 1907. An economic study of field mice (genus _Microtus_). U.S.D.A. Bull. Biol. Surv., 31:1-64, October 28, 1907. LOWERY, G. H., JR. 1943. Check-list of the mammals of Louisiana and adjacent waters. Occas. Papers Mus. Zoöl., Louisiana State Univ., 13:213-257, November 22, 1943. NELSON, E. W. 1893. Description of a new species of _Arvicola_, of the Mynomes group, from Alaska. Proc. Biol. Soc. Washington, 8:140-142, December 28, 1893. QUICK, E. W., and A. W. BUTLER. 1885. The habits of some Arvicolinae. American Nat., 19:113-118, February, 1885. _Transmitted August 13, 1946._ 21-6957 * * * * * Transcriber's Notes Italic text is shown within _underscores_. Bold text is shown within ~tildes~. Page 136, Table 3, under Compositae: changed Loctuca to Lactuca (_Loctuca scariola_) and changed artemsiifolia to artemisiifolia (_A. artemsiifolia_) Page 139: changed trappd to trapped (from live-trapped and some snap-trappd voles.) and changed rate to rat (the prairie vole and the cotton rate) Page 141: changed Almeda to Alameda (at Calaveras Dam, Almeda County, California,) Page 142: kept section heading: Mites (Acarina except Ixodoidea) (the TOC lists the variation Acari instead of Acarina) and changed Almeda to Alameda (at Calaveras Dam, Almeda County, California.) Page 143: changed tridecimlineaus to tridecimlineatus (ground squirrel (_Citellus tridecimlineaus_) at Lawrence.) Note: Another spelling variation is: tridecemlineatus. Page 146: changed table 2 to table 9 (A comparison of table 2 with figure 2 shows that the largest) Page 143: kept spelling variation: Dermacentor variabilis Page 149: kept spelling variation: Dermacenter variabilis Page 150: changed LITERAURE to LITERATURE (LITERAURE CITED) and kept spelling variation: agrestris, being a reference citation (1933. Factors affecting ... field mouse (_Microtus agrestris_)).