TEIID LIZARDS OF THE GENUS CNEMIDOPHORUS 197 



Strecker (1910. p. 9) placed the following- observations on record: 

 '* One niornino- near the water hole above camp I had the good 

 fortnnc to snri)riso a female in the act of depositing her oggs. She 

 was digging a hole in the loose sand, near the base of a shelving 

 bank, nsing her forefeet, tlie long toes of the hind feet assisting in 

 the operation by ])ushing the loose sand out of the excavation. 

 After going to a depth of nearly G inches she turned around and 

 began to deposit the eggs. At this period she became frightened 

 * * * and scurrie<l out of the hole * * * j found the eggs 

 covered with a thin layer of sand. This may have been her full 

 complement, for she was not more than two-thirds grown. The 

 hour was 7.30 a. m." 



The incubation period under normal, or even abnormal, conditions 

 has evidentl}' not been determined, and the date that the young come 

 from the egg is also unknown. The writer's field observations tend 

 to indicate that the 3'oung are not hatched before the latter part of 

 July (Texas, New Mexico, and Arizona). Euthven and Gaige (1915, 

 p. 2G) found a young specimen in the stomach of an adult on August 

 14 (Nevada). An individual observed by the writer at Hazen, 

 Churchill County, Nev., on August 25, 1928, was very young and 

 may have been hatched only a short time. 



Enemies. — Specimens of fcsseUatus no doubt form an item in the 

 natural menu of certain of the carnivorous desert mammals. Prob- 

 ably the house cat is a formidable enemy in the more settled regions. 

 Among birds, Grinnell and Grinnell (1907, p. 35) have reported 

 the collection of a road runner whose stomach contained four full- 

 sized whiptail lizards ! 



Euthven (1907, p. 5G3) observed the tessellated lizard being preyed 

 upon by the leopard lizard, Crofaphytus wislisenii, and Cowles 

 (1920, p. G4) has reported finding it in the stomach of not only this 

 form, but also in that of the collared lizard, Crofaphytus collaris. 



Of the snakes, apparently the genera Mastcophis and Crotakis are 

 the only ones that have been reported as enemies of this lizard, but 

 probably the subspecies is welcome prey to many kinds of snakes. 

 According the Euthven (1907, p. 5G3) the whiptail is preyed upon 

 by the red racer, Masticophis flagellum frenatus. This statement is 

 supported by Cowles (1920) Avho wrote that after shooting one of 

 these lizards and Avhile watching for an opportunity to kill it without 

 the use of a second shot, a racer glided into view and seized it. 

 Euthven and Gaige (1915, p. 2G) have said that the desert whiptail 

 is preyed upon by the striped racer, Masticophis taeniatus taeniatus. 

 A specimen of tesseUatus was obtained from the stomach of Grotalus 

 cerastes by Van Denburgh and Slevin (1913, p. 429), and it has been 

 claimed to form a part of the food of Grotalus tigris (Oi'tenburger 

 and Ortenburger, 192G, p. 111). 



