CALIFORNIA SEA SHELLS. 
28 
name. It is very plump and full, with a dozen 
distinct ribs on each side. Its color is reddish 
chocolate, with white teeth on the inner wall of 
the long and narrow aperture. It is a pretty 
little shell, from one-fourth to one-half inch in 
length, and is sometimes worn as a jewel. 
Erato vitellina , lids., Fig. 6, PI. Y, is about 
half an inch in length, quite smooth, with a 
large aperture and thickened outer lip. The 
spire is short ,and largely concealed. The per- 
istome is white, and the back is chestnut brown. 
Dead shells may frequently be found along the 
shore. 
Fig. 7, PI. Y, represents the natural size of 
the pretty little Erato columbella , Mke. This 
species has a visible spire, long aperture with 
finely toothed edges, white lips and olive back. 
Still smaller, but somewhat resembling this 
species, is the pure white Marginella Jewettii , 
Cpr., not figured. It is one-fifth of an inch long, 
has a rounded spire and four distinct folds near 
the base of the columella. It resembles the 
Pice Shell, Olivella oriza , but is shorter and 
thicker. 
Fig. 1, PI. YI, represents a moderate sized 
specimen of Lunatia Lewisni , Gld., Moon-shell. 
It sometimes grows to be five or six inches in 
diameter, and is a powerful enemy to helpless, 
burrowing bivalves. Plowing along through 
the wet sand by means of its enormous foot, it 
no sooner strikes an unfortunate clam than the 
head is stretched out, and the drill which it car- 
ries in its trunk started on its errand of destruct- 
ion. Its color is yellowish white; spire, slicrt; 
