764 



SCIENCE. 



[N. S. Vol. III. No. 73. 



May, 1892, to July, 1894, I had abundant 

 opportunity of verifying previous observa- 

 tions upon the life of Phrynosoma, and of 

 adding some notes that, so far as I can find, 

 have not been given before this paper. 



Phrynosoma cormitum Harlan, in Texan 

 parlance the ' horny frog, ' is easily ap- 

 proached under the natural conditions of 

 its habitat, and with a plentiful supply of 

 live flies I have had no difl&culty in keep- 

 ing from fifty to one hundred of them con- 

 fined in vivaria for many weeks at a time. 

 Six months of the hot, dry, Texas summer, 

 with long days under the glaring sun, and 

 the ground covered with a layer of fine, 

 limestone dust, gives this species of Phry- 

 nosoma an ideal environment. 



A review of the principal points con- 

 cerning the biology of this familiar genus 

 as brought out in the literature appended, 

 and confirmed by myself, may be first pre- 

 sented. Not to go back to the original sys- 

 tematic descriptions of Wiegmann, Girard, 

 Harlan, Hallowell, Bell, Gray and Blain- 

 ville, or to mention the synonymy from the 

 various catalogues of reptiles, the taxonomic 

 needs of this paper may be served by refer- 

 ence to Gentry's review of the genus Phry- 

 nosoma. 



This cunning little Iguanid is harmless, 

 never biting its captor, and soon becoming 

 so tame that it may be trained to work in 

 harness pulling a toy wagon, or to eat in- 

 sects from one's hand. When gently 

 rubbed it puffs itself out, but when in fear 

 it becomes fiattened to the ground. Phry- 

 nosoma chiefly enjoys a dust heap, where 

 with tail and feet flirting the warm calcare- 

 ous powder over its body, or with alternate 

 sawing motions of its sides, it quickly bu- 

 ries all of itself save the head, and some- 

 times even this part, in the dirt. While 

 built after an awkward pattern for a lizard, 

 and generally moving slowly, yet it can, 

 when alarmed, run rapidly. It is very 

 clever at 'playing possum' and, aided by 



its protective coloring, often escapes from 

 an enemy. 



The food of Phrynosoma always consists of 

 live animals — spiders, flies and especially 

 ants. In Texas the agricultural ant (Po- 

 gonoynyrmex barbatus) furnishes almost ex- 

 clusively the diet of the horned frog. If,, 

 however, a quantity of ants are placed with 

 the latter in a vivarium, they soon find thin 

 places on the apparently tough, horny ar- 

 mor of their enemies, and by stinging they 

 drive the horned frogs crazy and frequently 

 to death. While having an abundant sup- 

 ply of water in the vivarium, I have never 

 seen these lizards drink, although they are 

 said to lap up drops of dew when in natural 

 environment. The molting and the curi- 

 ous habit of ejecting blood from the eyes 

 are phenomena often observed. The state- 

 ment of Bottger that a voice is absent in 

 Phrynosoma must be modified, for under cer- 

 tain conditions of excitement it utters a 

 sharp squeak. 



This lizard has always been given aa 

 viviparous. On the contrary, it builds a 

 nest and lays eggs therein. The only time 

 I observed the nest-building was on June 

 25, 1894:. The location was on a stony clay 

 bank at the side of an Austin street. When 

 first seen, 6 p. m., the female was excava- 

 ting a tunnel at an angle of about 75° to the 

 surface of the ground, and wide and high 

 enough to comfortably work in. She dug 

 with her front feet, pushing back the loose 

 earth and bits of stone with her hind feet 

 until this debris was quite clear of the en- 

 trance. So absorbed was she in her work 

 that my presence did not cause any alarm. 

 The next morning I found the tunnel neatly 

 filled again and the lizard gone. 



After carefully removing the replaced 

 debris, the tunnel was found to be seven 

 inches deep. At the bottom, forming an L 

 with this tunnel, was a narrow entrance 

 leading into a chamber three and one-half 

 inches in diameter and two inches high,. 



