13. PHRYNOSOMA 415 



the lizard fills in around and over them with earth and is 

 ready for the next lot. In one nest examined by me, the 

 eggs were arranged in four layers of six each. It is really 

 marvelous how hard and firm the earth is packed into the 

 burrow. The period if incubation is about forty days, but I 

 presume that this depends largely on the condition of the 

 weather and the location of the nest. Several eggs hatched 

 out in my office on the 35th day, but I am certain that these 

 were several days incubated when they were brought in. In 

 my former notes I mentioned a set of eggs that were found 

 under an old railroad tie. This seems rather a peculiar 

 case when we consider the fact that the eggs are usually 

 buried to a depth of six or seven inches, but at the time this 

 set was found it had been raining steadily for several days 

 and the ground was wet and soggy. These conditions may 

 account for the seeming neglect of the lizard mother. Had 

 I not captured the female, I might have at first thought that 

 these eggs were those of some other lizard. At that date, 

 however, Cnemidophorus gulans was not breeding, in fact, 

 had only been active for a very few days, and it is the only 

 other species that would be likely to breed in such a situa- 

 tion. As far as my observations go, none of our other liz- 

 ards deposit more than a dozen eggs, and there were twenty- 

 four in the set mentioned. 



"The breeding season extends from the middle of April 

 into the latter part of July. The eggs have a tough, leath- 

 ery, non-calcareous shell. All of those in one set are usually 

 of the same shape, but when several sets are compared they 

 show considerable variation. The length in about seventy 

 specimens is about the same, but the diameter varies consid- 

 erably. The average type measures % of an inch in length 

 by 7/1 6 in diameter. In the fresh egg the color is yellowish- 

 white. Those in the set collected on July 10, 1906, are 



