36 
CALIFORNIA SEA-SHFLLS. 
eat the deepwater 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. Lucapina 
crenulata , Sby., Fig. 4, PI. IX, is a Ihuge mol- 
lusk, six inches or more in length. It is brick- 
sliaped, 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, crenellat- 
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, Fissurella volca- 
no , Rve, Fig. 3, PI. IX, has a very suggestive 
name. It is of an oblong, conical form, smooth- 
ish, about an incli 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 
