_Records of occurrence_ (in each state the localities are listed from north to south).--Chihuahua: Carimechi, Rio Mayo, 10 U. Mich.; 1-1/2 mi. SW Tocuina [Tocuina is a construction camp, in 1959, on NW bank of the Rio Septentrion, and is not the Tacuina shown on some maps SE of that River], 10 K. U.; Batopilas, 6 U. S. N. M. Durango: Chacala (Osgood, N. Amer. Fauna, 18:55, September 20, 1900). Sinaloa: Rancho Rosalita, 26 mi. NE Choix, 3 K. U.; 4 mi. NE Terrero, 6 K. U.; 1 mi. S Pericos, 20 K. U.; 12 mi. N Culiacan, 29 K. U.; 32 mi. SSE Culiacan, 20 K. U.; 6 mi. N, 1/2 mi. E El Dorado, 41 K. U.; El Dorado, 2 K. U. Sonora: Rio "Cuchahaque," 11.3 mi. E Alamos, 5 Univ. Arizona; 9 mi. SE Alamos, 1000 ft., 5 K. U. We have not seen any specimens that are intergrades between _P. goldmani_ and _Perognathus intermedius_ (subspecies _intermedius_ or _lithophilus_), nor between _P. goldmani_ and _Perognathus nelsoni_ (subspecies _nelsoni_ or _canescens_), nor between _P. intermedius_ and _P. nelsoni_. Collecting and studying specimens from geographically appropriate places to test for intergradation between these three species would be worthwhile as a means of improving our knowledge of the taxonomy of these mice. We are obliged to J. R. Alcorn and William L. Cutter for collecting many of the specimens used by us, to the Watkins Fund of the Kansas University Endowment Association and to the American Heart Fund for financial assistance with collecting the specimens, to the National Science Foundation for financial assistance with study of the specimens in the Museum, to William H. Burt of the University of Michigan, and to Stanley P. Young, Richard P. Manville and Viola S. Schantz of the Biological Surveys Collection of the United States Fish and Wildlife Service for lending certain specimens. _Transmitted October 1, 1959._ 28-1243 * * * * * Transcriber's Notes: Italicized text is shown within _underscores_. Bold text is shown within ~tildes~.