212 WEST COAST SHELLS 



of flight from such an enemy, and if its hard shell 

 is not a protection it is in a sad condition. And indeed 

 the case is sad, tor the limestone shell is no match 

 for the quartz drill, and when he has reached the 

 savory meat inside, the robber makes short work of 

 his victim. A high-handed proceeding, no doubt; 

 but then, it contrasts rather favorably with our way 

 of opening clams and oysters. 



The size of this shell varies greatly with its age 

 and condition. Specimens have been found as large 

 as six-inch globes, but such giants are nor common. 

 They are ordinarily the size of average apples. The 

 color is yellowish white, the surface nearly smooth, 

 and the umbilicus is large. To stop the ample aper- 

 ture there is a broad, horny umbilicus, brownish in 

 color. The genus Folyniccs includes those shells 

 of the Natica family which have horny opercula. 



Figure 205 shows us a fair- 

 sized specimen of Polynices 

 recliiziana^ Desh., the South- 

 ern Moon-shell. This species 

 is a southern form, more 

 smooth and less globular than 

 the last, and it is easily iden- 

 Fig 205 tihed by the thick, heavy 



patch of enamel which ex- 

 tends down the columella, and nearly or quite fills 

 the umbilicus. The shell is very solid and strong. 

 In color it varies between white and brown. Its 

 average length is perhaps two inches, though many 

 specimens are smaller. The large operculum is thin 

 and horn-like, without any trace of solid shell. 



