CHAPTER XIV. 



Gadinia— The Owl Shell— The White Cap— A Large 

 Family of Limpets and the Meaning of Their 

 Names; Changeable Forms — Sea-weed Limpets, or 

 Nacellas. 



IN the preceding chapter we have considered a num- 

 ber of mollusks whose shells have a slit or fissure 

 at the apex; in this one, let us note those which have 

 a solid shell. 



The first one on our list is named Gadinia reticu- 

 lata, Sby., Ga-din'-i-a re-tik-u-la'-ta. {Gadinia 

 radiata^ Cpr.) The natural size of the 

 shell is shown in Fig. 83. It is low-arched, 

 entire, and has a nearly central apex, from 

 which run radial ridges to the edge of the 

 Fig. 83. shell. These rays are crossed by deep lines 

 of growth, giving the shell a nettled or reticulated 

 appearance. Its color is white, and it is half an inch 

 in diameter. I have found a few specimens living 

 on a mussel-bearing ledge, near low- water mark. 



Of the many species of true Limpets which are 

 found on the west coast of the United States, the 

 largest is the Owl-shell, shown in Fig. 84, and whose 

 true name is Lottia gigaiitea^ Gray, Lot'-ti-a 



