Accounts of Subspecies 511 _Dipodomys ordii_ 511 _Dipodomys ordii richardsoni_ 511 _Dipodomys ordii oklahomae_ 514 _Dipodomys ordii compactus_ 515 _Dipodomys ordii sennetti_ 517 _Dipodomys ordii evexus_ 518 _Dipodomys ordii medius_ 519 _Dipodomys ordii obscurus_ 521 _Dipodomys ordii terrosus_ 523 _Dipodomys ordii fremonti_ 524 _Dipodomys ordii uintensis_ 525 _Dipodomys ordii sanrafaeli_ 526 _Dipodomys ordii panguitchensis_ 527 _Dipodomys ordii monoensis_ 528 _Dipodomys ordii ordii_ 530 _Dipodomys ordii luteolus_ 533 _Dipodomys ordii extractus_ 534 _Dipodomys ordii chapmani_ 536 _Dipodomys ordii montanus_ 538 _Dipodomys ordii cinderensis_ 540 _Dipodomys ordii fetosus_ 541 _Dipodomys ordii utahensis_ 543 _Dipodomys ordii columbianus_ 544 _Dipodomys ordii idoneus_ 546 _Dipodomys ordii priscus_ 547 _Dipodomys ordii celeripes_ 549 _Dipodomys ordii cineraceus_ 550 _Dipodomys ordii marshalli_ 551 _Dipodomys ordii inaquosus_ 552 _Dipodomys ordii attenuatus_ 553 _Dipodomys ordii fuscus_ 555 _Dipodomys ordii longipes_ 556 _Dipodomys ordii pallidus_ 558 _Dipodomys ordii nexilis_ 559 _Dipodomys ordii cupidineus_ 561 _Dipodomys ordii palmeri_ 562 Conclusions 563 Tables of Measurements 565 Literature Cited 571 INTRODUCTION The geographic range of the kangaroo rats, genus _Dipodomys_, extends from southern Canada south to the southern limits of the Mexican Tableland and from the Pacific Coast east to the eastern limits of the Great Plains in Kansas, Oklahoma and Nebraska. These animals are usually restricted to sandy soils in semiarid regions. The species _Dipodomys ordii_, with which this account is primarily concerned, is, to the best of my knowledge, almost exclusively confined to sandy areas.