90 



points of sympatric hybridization was nnade. The overail hybrid index 

 for the li characters analyzed places the hybrids exactly intermediate 

 between the parental forms; the hybrids resemble one or the other par- 

 ent more closely when individual characters are considered. Thus _C. 

 perplexus represents an unsuccessful hybridization event in this genus 

 spanning a period of over 100 years. The three hybrid localities (8.^^ 

 mi. W. of Hatch, Dona Ana Co; 9 mi. E. of La Joya, Socorro Co; San Pe- 

 dro Creek and Tanque Arroyo, Sandoval Co.) exhibit disturbed or ecoton- 

 al habitats. A fourth hybrid locality mentioned but not reported on 

 here is in the vicinity of Mesilla, Dona Ana County. 



251. — . and — . 1968. Weeds, polyploids, parthenogenesis and the 

 geographical and ecological distribution of all-female species of 

 Cnemidophorus . COPEIA 1968(1): 128-137. 



The parthenospecies exsanguis , flagellicaudus , neomexicanus , 

 sonorae , tesselatus , uniparens and velox are each ecologically char- 

 acterized. The primary center of distribution of these forms is the 

 North American southwest adjacent to the Continental Divide and the 

 area of confluence between the Rocky Mountains and the Mexican Pla- 

 teau. The habitats occupied by the various species are diverse but 

 can be defined as "weed habitats". The presence of such habitats at 

 the time of origin of parthenogenetic individuals from hybridization 

 between bisexual species is a critical factor and the features that 

 contribute to the perpetuation of the parthenospecies are discussed. 



252. Yousef, I. M., W. G. Bradley and M. K. Yousef. 1977. Bile acid 

 composition of some lizards from the southwestern United States. PRO- 

 CEEDINGS SOC. EXPERIMENTAL BIOLOGY AND MEDICINE 15M1): 22-26. 



Nine species from Nevada, including Cnemidophorus tigris , were 

 studied. At least 6 different acids were present in this species, with 

 cholic acid being the primary one. Teiids and Gekkonids had very simi- 

 lar compositions. 



253. Zweif el, R. G. 1958. Cnemidophorus tigris variolosus , a revived 

 subspecies of whiptail lizard from Mexico. SOUTHWEST. NAT. 3: 94-101. 



Morphological and distributional attributes of C nemidophorus tig- 

 ris marmoratus are discussed. 



25'J. — . 1962. Analysis of hybridization between two subspecies of 

 the Desert Whiptail lizard, Cnemidophorus tigris. COPEIA 1962: 7^^9-66. 



