UNIVERSITY OF KANSAS PUBLICATIONS MUSEUM OF NATURAL HISTORY Volume 9, No. 15, pp. 397-404 December 19, 1958 New Subspecies of the Rodent Baiomys From Central America BY ROBERT L. PACKARD UNIVERSITY OF KANSAS LAWRENCE 1958 UNIVERSITY OF KANSAS PUBLICATIONS, MUSEUM OF NATURAL HISTORY Editors: E. Raymond Hall, Chairman, Henry S. Fitch, Robert W. Wilson Volume 9, No. 15, pp. 397-404 Published December 19, 1958 UNIVERSITY OF KANSAS Lawrence, Kansas PRINTED IN THE STATE PRINTING PLANT TOPEKA, KANSAS 1958 27-5660 New Subspecies of the Rodent Baiomys From Central America BY ROBERT L. PACKARD The southern pygmy mouse, _Baiomys musculus_, is known as far north as the Mexican states of Jalisco, Michoacán, south of the Mesa Central, east to central Veracruz (see Hooper, 1952a:90), and south to western Nicaragua (see Goodwin, 1942:161). Previously, two subspecies have been recognized from the southern part of the known range of this species: _B. m. nigrescens_, blackish mice from Chiapas, México, and Guatemala, and _B. m. grisescens_, grayish-brown mice from Honduras and western Nicaragua. Study of recently acquired specimens from Guatemala, El Salvador, and Nicaragua reveals two additional subspecies. For the loan of comparative material, I am grateful to the United States National Museum (USNM) and the American Museum of Natural History (AMNH). Unless otherwise indicated, specimens are in the University of Kansas Museum of Natural History. Measurements are as taken by Hooper (1952b:10). Postpalatal length is the distance from the posterior margin of the hard palate to the anterior margin of the foramen magnum. Unless otherwise noted, statistical significance as used in this paper is at the 95 per cent confidence limit or higher. The two heretofore undescribed subspecies are characterized below and may be known as: =_Baiomys musculus handleyi_=, new subspecies _Type._--Adult female, USNM No. 275604 (Biological Surveys Collection), skin and skull; from Sacapulas, El Quiché, Guatemala; obtained on April 24, 1947, by Charles O. Handley, Jr., original number 991. _Distribution._--Known only from the type locality; probably inhabits parts of the east-west drainage of the Río Negro.