SHELES WELHOUD CANALS 235 
flat sides. White, with fine brown stripes radiat- 
ing from the apex. It is a little shell, being only 
from 6 to 12mm. in length. It is a southern 
species, and may be found on grass at low tide. 
Acmea paleacea, Gld., the Chaffy Limpet, (Na- 
cella paleacea), has a very small shell resembling 
that of the last species, but still narrower. It is 
brownish, without stripes, and is 7mm. long. 
Acmea triangularis, Cpr., is probably a variety 
of the same species. 
The largest limpet to 
be found on the coast is 
the one whose shell is 
shown in Figure 259. Its 
name is Lottia gigantea, 
Gray, commonly known 
as the Owl-shell. On the 
outside it is usually 
rough, brown and un- 
sightly ; within it is very 
dark and lustrous, and 
has a bluish-white cen- 
ter marked with brown. 
In many specimens the part within the horse-shoe- 
shaped muscle-scar greatly resembles a horned 
owl sitting upon his perch. The shell is rather flat, 
and the apex is near one end. The length of the 
shell is sometimes as much as three inches, though 
commonly it is much less. When properly pol- 
ished, these shells make very pretty bowls for 
ornamental spoons. 
