94 BULLETIN 15 4, UNITED STATES NATIONAL MUSEUM 



" The many specimens used in the writer's experiments ate flesh 

 flies, leaf hoppers, tree hoppers, harvestmen, skipper butterflies, 

 lightning bugs, tarnished i)lant bugs, dingy cutworm moths, striped 

 cucumber beetles, grasshoppers, tree crickets, houseflies, measuring 

 worms, lacewings, green stinkbugs, alfalfa butterflies, and the corn 

 ear-worm mouth, with relish. Ground beetles were eaten only when 

 the elytra were removed, showing the lizard's preference for the 

 softer bodied insects. Large butterflies, such as the swallowtails, were 

 often killed, but not eaten. Lady beetles were always watched in- 

 tently, but if taken into the mouth were rejected." " The race runner 

 darts upon many victims in quick succession when at the height of its 

 feeding activity." (Burt, 1928Z>, p. G5.) 



It eats cockroaches and tiger beetles, according to Hartman (1906), 

 and Ditmars (1907) noted that " adults are not averse to feasting on 

 eggs of small birds that build their nests on the ground." In regard 

 to the latter statement, the Avriter (19286, p. 59) has written that 

 " after considering the size of the lizard's mouth, it appears that only 

 extremely small eggs, if any, would be eaten," and it seems that the 

 lizard can not be a serious enemy to bird life in this respect. 



Loennberg (1902, p. 35) found that the caecum is absent from the 

 digestive tract of sexlineatus^ and after the examination of a number 

 of stomachs, concluded (p. 29) that the form is chiefly insectivorous, 

 although some pieces of vegetable matter were found in the large 

 intestine. 



Of 29 specimens from Oklahoma examined by Force (1925, p. 26), 

 11 had empty stomachs. The remaining 18 contained Locustidae to 

 the extent of 52 per cent; Arachnida, 15 per cent; Myrmiciclae and 

 Formicidae, 16 per cent; Elateridae, 3.5 per cent; larvae, 9 per cent; 

 may fl}' nymphs, 1 per cent ; and mosquito wigglers, 1 per cent. 



The examination of the stomachs of 15 Kansas specimens (Burt, 

 19285, p. 60) revealed the following in the contents: Grasshoppers, 

 crickets, katydids, moths, measuring Avorms, beetles, bugs, ants, 

 chalcid flies, ichneumon flies, tachinid flies, spiders, and land snails. 



The race runner is fond of spiders and many small insects, espe- 

 cially grasshoppers and Lepidoptera. The finding of a total of 7 

 land snails in the stomach of the 15 Kansas specimens examined 

 suggests that these snails may form a substantial part of tlie lizard's 

 natural menu. 



Life history. — The eggs of sexJineatus are similar to those of 

 Sceloporus undiilatus undulafus (Brimley, 1903, p. 265), but some- 

 what larger, about 17 to 22 mm. long by 11 to 14 mm. broad, with 

 a smooth skin to which the dirt does not adhere so readily as to 

 the rough skin of the ScelojJorus eggs, and hence they usually look 

 much whiter. The markings on the embryo do not show until a week 

 or two l)efore hatchino:. 



