Probable interspecific hybridization is described between the red fox, Vulpes fulva, and the desert kit fox, Vulpes macrotis. The range of overlap of V. fulva and V. macrotis includes Reagan, Crockett, and Glasscock Counties, Texas. Descriptions of probable first generation hybrids are given based on body size, pelage coloration, and cranial characteristics. Data indicate that probable hybridiza- tion is limited in extent with no evidence of introgressive hybridization in the zone of overlap in western Texas. Two possible isolating mechanisms are considered: time of denning and ecological preference. Available evidence indicates an overlap in times of denning for V. macrotis and V. fulva. There appears to be no preference for choice of den sites. The taxon V. macrotis may be reaching eastern limits of eco- Field collecting and observations in Reagan County, Texas, indicate the presence of possible hybridization between the desert kit fox, Vul- pes macrotis, and the red fox, Vulpes fulva. The purpose of this report is to present evidence for probable interspecific hybridization. In ad- dition the discussion will include a consideration of the extent of pre- sumed hybridization and the possibility of introgression. Presumed interspecific hybridization is based on pelage coloration, body size, and cranial characteristics. Literature descriptions of kit foxes indicate that both the desert kit fox and plains kit fox, V. velox, are similar in general pelage coloration (Barnes, 1927; Grinnell, et al., 1937). Pelage coloration has been ex- amined on six examples of V. macrotis from Upton, Glasscock, and Reagan Counties. Coloration is similar in each case to literature de- scriptions. Three of the animals are represented by museum skins de- posited in the vertebrate research collection at Angelo State University (Cat. No. 249, 274, and 363). Two of the six examined are alive in laboratory cages. The sixth specimen was not saved. For the purpose of later comparison with probable hybrid pelage coloration a microscopic examination of guard hairs covering the dorsal body surface is pertinent. Individual guard hairs are seen to be black or multicolored. Microscopic examination reveals that multicolored hairs predominate. Most of the length of each multicolored hair consists of