Maxillary tooth row.--The greatest length of the upper molariform tooth row at the alveolar border. Extension of premaxillae posterior to nasals.--From the posteriormost border of the nasals to the posterior end of the extension of a premaxilla. Depth of skull.--From the median suture of the frontals, on the dorsal surface of the skull to the median suture of the palatines at the level of the first molar (not premolar). Length of rostrum.--From the anterior border of the nasal to the maxilla at the lateral end of the hamulus of the lacrimal. In the list of specimens examined, localities are arranged by counties from west to east, beginning at the northwestern corner of the state; specimens in each county are arranged from north to south. If several localities are in the same latitude, the westernmost is listed first. Capitalized color terms are after Ridgway, Color Standards and Color Nomenclature, Washington, D. C., 1912. [Illustration: FIG. 1. Map showing the geographic distribution of the five subspecies of the Mississippi Valley pocket gopher, _Geomys bursarius_, in Kansas, with insert showing range of the species.] In connection with this study each of the authors acknowledges assistance from the John Simon Guggenheim Memorial Foundation and one of us (Villa) is grateful for assistance also to Drs. Isaac Ochoterena and Roberto Llamas of the Biological Institute of Mexico. For the loan of specimens we are grateful to Dr. William B. Davis, of the Agricultural and Mechanical College of Texas; Dr. G. C. Rinker, of Hamilton, Kansas; and Mr. A. J. Kirn, of Somerset, Texas. Unless otherwise indicated, specimens are in the University of Kansas Museum of Natural History. ACCOUNTS OF SUBSPECIES =Geomys bursarius lutescens=, Merriam _Geomys bursarius lutescens_ Merriam, North Amer. Fauna, 4:51, October 8, 1890; Scheffer, Technical Bull., U. S. Dept. Agric., 224:6, January, 1931. _Geomys lutescens_ Merriam, North Amer. Fauna, 8:127-29, January 31, 1895; Lantz, Trans. Kansas Acad. Sci., 19:175, 1905; Lantz, Kansas State Agric. College Bull., 129:335, April, 1905; Hibbard, Trans. Kansas Acad. Sci., 36:240, 1933; Black, 30th Bienn. Rept. Kansas State Board Agric., 35:182, 1937; Swenk, Missouri Valley Fauna, 2:1, February 1, 1940; Allen, Kansas State Teachers College, Emporia, Bull. Inf. in Educ., 20 (no. 5):15, May, 1940; Hooper, Occas. Papers Mus. Zoöl., Univ. Michigan, 420:3, June 28, 1940. _Geomys lutescens lutescens_, Hibbard, Trans. Kansas Acad. Sci., 47:74, 1944. _Type locality._--Sandhills on Birdwood Creek, Lincoln County, western Nebraska. _Distribution in Kansas._--Northwestern Kansas, eastward certainly to Ellis County, southward certainly to Scott County.