77 



202. Schmidt, K. P. and T. F. Smith. 19^4. Amphibians and reptiles 

 of the Big Bend region of Texas. FIELD MUSEUM OF NATURAL HISTORY 

 ZOOLOGICAL SERIES 29(5): 75-96. 



Habitat differences are sharply defined between Cnemidophorus 

 grahamii (= tesselatus), which lives in canyons, and _C. tessellatus 

 (= tigris), which occupies desert flats or plateaus. 



203. Schrank, G. D. and R. E. Ballinger. 1973. Male reproductive 

 cycles in two species of lizards (Cophosaurus texanus and Cnemidophorus 

 gularis ). HERPETOLOGICA 29(3): 289-293. 



Histological studies were done on specimens from Tom Green County, 

 Texas. Males emerge from hibernation with relatively small testes which 

 rapidly increase in size to a maximum in May followed by gradual gonadal 

 regression until September. This parallels female ovarian cycles. Fat 

 bodies are almost depleted during the cycle. 



20'^. Scudday, 3. P. 1971? The biogeography and some ecological 

 aspects of the Teiid lizards (Cnemidophorus ) of Trans-Pecos Texas 

 (August 1971). Ph.D. DISS., TEXAS A <5c M UNIVERSITY. 198 p. 



Field studies of sympatric relatidnships among Cnemidophorus 

 exsanguis , _C. gularis gularis , _C. inornatus heptagrammus, _C. tesselatus 

 E and C. tigris marmoratus were conducted to obtain a better understand- 

 ing of speciation processes in the genus. Populations of all the 

 species in the region were compared morphologically and 2 new pattern 

 classes of _C. tesselatus described. Geographic and ecological distri- 

 butions are discussed in detail. Minor differences in food items be- 

 tween species are thought to be important during adverse times. Species 

 behaviors are discussed; _C. inornatus heptagrammus was found to be the 

 most aggressive species under captive conditions. Foraging behavior was 

 found to be a significant measure of niche separation. Reproduction was 

 investigated; all species produced 2 clutches a year. Unbalanced sex 

 ratios favoring males found in _C. tigris marmoratus is thought to be a 

 contributing factor in the hybrid origin of _C. tesselatus . Ecological 

 and evolutionary sympatry and competition is discussed. Changes in 

 species composition and density due to yearly climatic fluctuations were 

 observed. 



205. — . 1973. A new species of lizard of the Cnemidophorus 

 tesselatus group from Texas. J. HERPETOLOGY 7W: 363-371. 



Cnemidophorus dixoni is formally named, and morphological descrip- 

 tions and a diagnosis are given. Differences in color pattern are the 



