_Dipodomys ordii compactus_, Davis, Journ. Mamm., 23:332, August 14, 1942. _Type._--None designated but Poole and Schantz (1942:406) assumed it to be a female, no. 19665/35227, only the skin found, from Padre Island, Cameron County, Texas. April 3, 1888. Purchased from C. K. Worthen. _Range._--Padre and Mustang islands, Cameron County, Texas. _Diagnosis._--Size medium (see measurements); tail short. Color light; entire dorsal surface Light Ochraceous-Buff, purest on sides and flanks, upper parts but lightly suffused with black. A lighter color phase has entire dorsal surface Cartridge Buff, purest on sides and flanks, upper parts but lightly washed with black. In both phases, cheeks white; pinnae of ears, plantar surfaces of hind feet, dorsal stripe of tail, ventral stripe of tail (in most specimens) present on proximal third of tail only, brownish. Skull small; rostrum narrow and long; nasals long; auditory bullae inflated, but greatest breadth across bullae only slightly more than breadth across zygomatic processes of maxillae; interparietal region wide. _Comparisons._--From _Dipodomys ordii sennetti_, _D. o. compactus differs_ in: Size slightly less; color lighter in all pigmented areas; skull smaller; auditory bullae slightly less inflated; interorbital width less; interparietal region wider; nasals longer. From _Dipodomys ordii attenuatus_, _D. o. compactus_ differs in: Body larger; tail shorter; normal color phase darker, and lighter color phase lighter; skull larger; rostrum wider and longer; nasals longer; interorbital region wider; auditory bullae relatively as well as actually less inflated; interparietal region wider; pterygoid fossae large and round as opposed to small and ovoid. Compared with _Dipodomys ordii medius_ and _Dipodomys ordii ordii_, _D. o. compactus_ is smaller, lighter in color, and has less inflated auditory bullae and a smaller skull. _Remarks._--This subspecies of _Dipodomys ordii_ was originally described as _Dipodomys compactus_ by True in 1889 and stood as a full species until Davis (1942:332) relegated it to subspecific status under _Dipodomys ordii_. Davis (_op. cit._) observed close resemblances in external proportions, size of mastoid bullae, width of supraoccipital, and size and shape of the interparietal, between _Dipodomys ordii_ and _Dipodomys sennetti_ and therefore concluded that they were only subspecies of one species. He observed that the difference between _Dipodomys compactus_ and _Dipodomys sennetti_ was of approximately the same degree as that between _Dipodomys sennetti_ and _Dipodomys ordii_. From this he concluded that all three were subspecies of the one species _Dipodomys ordii_.