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PROCEEDINGS OF THE NATIONAL MUSEUM 



Table 11. — Present centers of distribution of the Zuni herpetofauna 

 Transcontinental North America 



Ambystoma tigrinum 

 Bufo woodhousei 

 Pseudacris triseriata 

 Rana pipiens 



Sceloporus undulatus 

 Diadophis punctatus 

 Masticophis flagellum 

 Pituophis melanoleucus 



Western North America 



Scaphiopus inter montanus 

 Crotaphytus collaris 

 Sceloporus graciosus 

 Uta stansburiana 

 Urosaurus ornatus 

 Phrynosoma douglassi 

 Cnemidophorus velox 



Mexican Plateau 



Scaphiopus hammondi 

 Bufo punctatus 

 Hyla arenicolor 

 Holbrookia maculata 



Scaphiopus bombifrons 



Great Plains 



Eumeces multivirgatus 

 Thamnophis elegans 

 Masticophis taeniatus 

 Hypsiglena torquata 

 Crotalus atrox 

 Crotalus viridis 



Thamnophis dorsalis 

 Salvadora grahamiae 

 Crotalus molossus 



Eumeces obsoletus 



Patterns of Distribution 



Three widespread species, Sceloporus undulatus, Urosaurus ornatus, 

 and Hypsiglena torquata, contain one geographic race restricted to the 

 greater Colorado Plateau region and another to the southeastern 

 Basin and Range province. These intergrade in the Zunis and else- 

 where along the southern border of the Plateau.^ Bujo woodhousei, 

 Pseudacris triseriata, Uta stansburiana, Eumeces multivirgatus, and 

 Pituophis melanoleucus, from the same distributional groups (trans- 

 continental and w^estern North America), have similar patterns of 

 restricted gene exchange, but their northern subspecies are m no sense 

 limited to the Plateau. It is significant that a past or present break in 

 the gene flow of these eight eurytopic forms coincides with the Colorado 

 Plateau-Basin and Range border. 



Scaphiopus bombifrons and Eumeces obsoletus, the two Great Plains 

 species, and Salvadora grahamiae and Crotalus molossus, centered on 

 the Mexican Plateau, are at or near the northern limits of the south- 

 western portions of their range in the Zunis. They have not pene- 

 trated Colorado Plateau highlands except along a few major river 

 valleys. The five other species allied with the Mexican Plateau range 

 somewhat further north but not beyond the upper Colorado River 



8 Holbrookia maculata and Crotalus viridis also may fit this pattern in part, but 

 the Colorado Plateau subspecies involved are defined inadequately at present. 



