TEIID LIZARDS OF THE GENUS CXEMIDOPHORUS IQ 



Ilah'itat. — There is oreat diversity in the type of habitat oeciipieil 

 hy the various forms, and even by the popuhitions or phases of the 

 same form. As shown by Cope (1892c', p. 30), ''The species of 

 C nemkloplio'i'us usually inhabit dry, open places where they can ob- 

 serve their insect prey and wateli their enemies. From the latter 

 they escape by the extreme rapidity of their movements, which 

 renders it difficult to follow them with the eye, to Avhich they appear 

 as a streak flying over the ground." 



GadoAv (1906, p. 278), after working in Mexico, offered the follow- 

 ing comment : " AVhen, as in Guerrero, during the rainy season a 

 dense mass of herbs springs up almost everj^where, no ground lizards 

 can be seen except in the narrow tracks across which they flit to 

 hide in the tangle upon being warned by our approach. Moreover, 

 the}^ are very local, and they do not always appear. Rain, certain 

 winds, or a dull sky may keep them in their lairs. One may ride 

 for days and not see a single specimen. Then suddenly there may 

 be hundreds, and what are really members of one clan or even of 

 one family may be collected. The next few days again may yield 

 nothing or only a single specimen here and there ; and this is really 

 worse than nothing, for it leaves it undecided whether its characters 

 are truly typical of that district, or merely individual." 



* * * " Mexico is an ideal country for the study of geograph- 

 ical distribution, because it contains, often in juxtaposition, vast 

 semideserts, high plateaus, big continuous ranges of mountains with 

 peaks in the eternal snow, hot lowlands of the Atlantic or humid 

 type with luxurious rain forests, and of the Pacific or drier type; 

 large forests of pines, oaks, or of tropical trees; rivers and lakes; 

 regions of enormous fertility and hopeless deserts. In short, every 

 climate and every conceivable kind of bionomic condition is to be 

 found in this country. No wonder that such diversity is expressed in 

 the well-nigh endless kaleidoscopic variation of Cnemidojjhonis, the 

 main genus of strictly humivagous lizards of the countr3\" 



It may be remarked here that similar conditions and variations 

 to those described above may be found in the United States and in 

 Lower California. An elaboration of this subject will be found 

 below in the discussion of the various forms. 



TIahits. — ]Most of the notes relating to habits are based upon more 

 or less sketchy field observations and pertain chieflj' to the be- 

 havior of these lizards after being disturbed by the collector. Also, 

 the results obtained from various examinations of stomach contents 

 have been recorded. The available data tend to indicate that the 

 species of Cnemulophorus are egg-laying, diurnal, chiefly insectiv- 

 orous animals. The details pertaining to the life-history of most 

 of the forms remain entirelv unknown. 



