Abstract
Nongeographic and geographic variation were assessed in 20 samples (224 specimens) of Ord's kangaroo rat (Dipodomys ordii) from southern Texas and northern Mexico. Univariate and multivariate analyses were employed in consideration of geographic variation. Dipodomys compactus is arranged as a separate species from D. ordii and four races of D. compactus (compactus, sennetti, largus, and parvahultaliis) are recognized. Both compactus and ordii possess different karyotypes and animals with these distinct karyotypes occur in south Texas without evidence of interbreeding.
