36 CALIFORNIA SEA-SHELLS. 



eat the deep water species, and perfect shells may 

 sometimes be found in their stomachs. 



The coast of California abounds in limpets; 

 they may be found in countless numbers clinging 

 to the rocks, their cup-shaped shells protecting 

 their soft bodies from injury. They crawl along 

 the surface of the rock, and many of them, like 

 the famous birds, " come home to roost." Some 

 old ones may be found settled some little dis- 

 tance into that spot on the rock which has long 

 been their home ; sometimes the roost is on the 

 shell of another limpet, which becomes indent- 

 ed in the same manner. We will first note those 

 which have a hole in the shell, and are thus con- 

 nected with the preceding genus. Lucapnna 

 crenulata, Sby., Fig. 4, PI. IX, is a )huge mol- 

 lusk, six inches or more in length. It is brick- 

 shaped, with a broad yellow foot, black mantle, 

 and has a shell on the back, largely concealed by 

 the folds of the mantle, This shell, shown in 

 the figure, is marked by radiating ribs, crenulat- 

 ed edge, oblong hole, and concentric lines of 

 growth. Internally, it is of a pure, glossy white, 

 with a thick rim of enamel around the hole. 

 This mollusk is not abundant. 



The next Key-hole Limpet, Fissurclla volca- 

 no, Eve, Fig. 3, PI. IX, has a very suggestive 

 name. It is of an oblong, conical form, smooth- 

 ish, about an inch in length, with red stripes 

 running from the fissure to the edge, resembling 

 streams of hot lava from a crater. It may occa 

 sionally be found living at very low water. Gly- 

 phis aspera, Esch., is larger, with a small, oval 

 hole; white, with some color rays; very rough and 



