ON CLAY 



213 



a) Subterranean-ground stratum. — Perhaps the most characteristic 

 animal of the steep bluff is the bluff tiger-beetle (55, 151) (Cicindela 

 purpurea limbalis) (Figs. 159-67). In the open places of this stage, the 

 larvae, which live in curved cylindrical burrows (Figs. 165, 166), are 

 common. 



The female beetle is provided with an ovipositor (Fig. 159) adapted 

 to making small holes in the clay in which eggs are laid (Figs. 160, 161). 



ft.& 



' t ,"J& 



66 



168 



& 



69 



Clay-Bank Inhabitants 

 Fig. 166. — View of larval burrow of the tiger-beetle; natural size. 

 Fig. 167.— The adult tiger-beetle {Cicindela limbalis); about twice natural size. 

 Fig. 168.— The clay-bank spider (Pardosa lapidicina). 

 Fig. 169.— A snail of the shrub stage (Polygyra monodon); enlarged. 

 Fig. 170. — The snail (Polygyra thyroides) ; enlarged. 



The larva (Figs. 162, 163) on hatching from the egg digs a burrow in the 

 position of the ovipositor hole. The eggs, which are laid in June, hatch 

 in two weeks and the larvae live in the spot where the eggs were laid 

 for one year, and transform into pupae (Fig. 164) in the ground in an 

 especially prepared cavity (Fig. 165). The adult, which is a reddish- 



