SNAKES OF THE GENUS PITUOPHIS 155 



.... While kept in the laboratory, copulation was attempted several times. 

 . . . Although there were two other gopher snakes of about the same size in the 

 cage with this pair, there were no signs of friendship toward them by either of 

 the mated pair in question. The male and the female stayed in the same part 

 of the cage and seldom mingled with the other snakes, though there were no 

 hostile actions. ... On August 7, five eggs were found in the cage in the corner 

 with the female, and the next day five more were laid. . . . They . . . were 

 found scattered about the corner of the cage occupied by the female. There was 

 no noticeable attempt on the part of the female to protect, or maintain contact 

 with, the eggs. On August 9, I opened one of the eggs and found an embryo 

 within, well started in development. Embryonic development had evidently 

 begun some time previous to the laying of the eggs. [An attempt to hatch the 

 eggs was unsuccessful.] 



Affinities. — The closest aflBnities of catenijer catenifer arc undoubt- 

 edly with the forms c. deserticola and c. annedens. Although in the 

 number of dorsal spots there is a continuous increase from deserticola 

 to catenifer to annedens, most of the scale coimts show a decrease from 

 deserticola to catenifer but not to annedens. This seems to indicate 

 that both catenifer and annectens are derived directly from deserticola 

 and exhibit different evolutionary tendencies in scale variation, but a 

 similar tendency in pattern variation, which is, however, further 

 developed in annectens than in catenifer. The probable relationships 

 of these forms have been expressed by the diagram on page 133. 



Table 12 lists the specimens of this form that have been examined. 



136423—40 11 



