87 



cies). It is suggested that some ecological species definitions lead 

 to underestimations of the rate of extinction due to interspecific com- 

 petition because their logical frameworks exclude unsuccessful species 

 from being considered species. 



239. Willard, D. E. 1966, The thermoecology of Cnemidophorus tigris . 

 PH.D. DISSERTATION, UNIVERSITY OF CALIFORNIA-DAVIS. 99 p. 



A population in central California was studied for three years. 

 Lizard body temperatures were closely correlated with substrate temper- 

 atures. Body temperatures of active lizards ranged from 33 to ^1°C. 

 The mean body temperature of juveniles is lower than that of adults. 

 Seasonal activity is bimodal. The thermal characteristics of microhab- 

 itats lizards utilized were measured and correlated with lizard activi- 

 ty over the study period: the first year was optimal, the second too 

 hot and the third too cold. _C. tigris was more active, abundant and 

 enjoyed higher reproductive success over the first year than over the 

 other two. Emergence and retreat depend upon favorable thermal micro- 

 habitats and releasing subsurface temperatures of 30-33°C. Lower re- 

 productive success was caused by high temperatures reducing favorable 

 egg deposition sites and intraspecific interference with foraging acti- 

 vities during shortened activity seasons (from abstract). 



2W. Williams, K. L. 1960. Taxonomic notes on Arizona herpetozoa. 

 SOUTHWESTERN NATURALIST 5(1): 25-36. 



Some morphological characteristics for Cnemidophorus burti sticto - 

 grammus are given. A review of diagnostic characters of _C. tigris gra - 

 cilis and _C. tigris septentrionalis is presented and range maps (now ob- 

 solete) given. 



2<fl. — , H. M. Smith and P. S. Chrapliwy. 1960. Turtles and lizards 

 from northern Mexico. TRANS. ILLINOIS ST. ACAD. SCI. 53(l(k2): 36-^^5. 



Cnemidophorus tesselatus was collected along the Rio Florida in 

 northern Chihuahua in vegetation of willows, cottonwoods, and fairly 

 heavy undergrowth. _C. tigris marmoratus was collected from the same 

 vicinity. 



2*2. Wright, 3. W. 1963. Cnemidophorus gularis in New Mexico. 

 SOUTHWESTERN NATURALIST 8(1): 56. 



Two specimens from the state are reported. The systematic uncer- 

 tainty regarding this taxon as it pertains to confusion over the occur- 



