TEIID LIZARDS OF THE GENUS CNEMIDOPHOKUS 139 



Food and fecdf'nfj Jiahits. — This form is an active feeder. Coues 

 (1875, p. 603) wrote of it as follows: "It used to frequent onr 

 tents during the summer, and hunt for flies in a quiet, furtive man- 

 ner, catching them with great address, and was very favorably 

 regarded by all on this account, although its labors resulted in no 

 sensible diminution of the pests." Although this species is quite 

 at home among the rocks and boulders, it probably feeds exclusively 

 on the ground, as suggested by Ortenburger and Ortenburger (1920, 

 p. 110), who stated that "More than once this wdiiptail was seen 

 on the sand among the boulders, eating. Its actions remanded us 

 very much of a chicken, except that the forefeet were used for 

 scratching, rather than the hind feet. It usually made two or three 

 scratches with one foot backward and laterally, and then two or 

 three with the other foot. They were in no case observed to make 

 alternate strokes. After every few scratches they would stop to 

 l^ick up some food by making very rapid, quick movements, again 

 reminding one of a chicken. They showed very little fear, for as 

 this process was observed they continued their activity for several 

 minutes in several instances. They would occasionally turn the 

 head and look at us and then continue eating.*' According to 

 Ruthven (197, p. 57), the food consists of insects which it picks 

 up from the ground. 



The stomachs of very few specimens have been examined. Ruth- 

 ven found beetles, ants, grasshoppers and spiders in the contents, 

 and Woodbury (1928, p. 18) added caterpillars to the list. 



Life hhfoiy. — The details pertaining to the life history of this 

 form remain practically unknown. Ortenburger and Ortenburger 

 (1926, p. 110) stated that ''One evening (July 15) at 6 p. m. a fe- 

 male containing well-developed eggs was dug out of a freshly made 

 hole about IVo inches in diameter and 1 foot deep. This hole had 

 been dug in the clean sand in a dry stream lied about a half mile 

 up a canyon. There was little doubt that the female caught had 

 dug the hole herself and possibly intended to deposit her eggs there." 



Eneinies. — One of these lizards was removed from the stomach of 

 a snake, Salvadora graJiamlae hexalepis^ at Fort Whipple, Ariz., by 

 Coues (1875, p. 620). 



Affinities. — The closest relative of fer'plexus is apparently gularis., 

 Avith Avhich it now intergrades over an extensive area in northern 

 Mexico on a line extending in general from Guaymas to northern 

 Coahuila, and, in the United States, northward to the panhandle of 

 Texas. Intergrading individuals often have the dorsal markings 

 of perplexus and the blue-black venti'al coloration of f/ukwi/^, but at 

 times the opposite condition is found. Both of these modifications 

 mei-ge insensibl}^, one into the other, along the line of intergrada- 

 tion. After considering this definite transition, and the proportional 



