228 WEST AMERICAN SHEERS 
The size of this shell varies greatly with its age 
and condition. Specimens have been found as 
large as six-inch globes, but such giants are not 
common. They are ordinarily the size of average 
apples. ‘The color is yellowish-white and the 
form spheroidal; the surface is nearly smooth, 
and the umbilicus is large. 
Polynices (Nevérita) 
recluziana, Petit, the 
southern Moon-shell, Fig- 
ure 248. This species is 
a southern form, more 
smooth and less globular 
than the last, and is easily 
Fig. 248 
identified by the thick, 
heavy patch of enamel which extends down the 
columella, and nearly or quite fills the umbilicus. 
The shell is very solid and strong. In color it 
varies between brown and white. Its average 
length is perhaps two inches, though many speci- 
mens are smaller. The large operculum is thin 
and horn-like, without any trace of solid shell. 
Natica clausa, Brod. and Sby., the Closed Natiea, 
is found in British Columbia and northern waters 
generally. It resembles Figure 247, but is easily 
distinguished by its closed umbilicus and its shelly 
operenlum. 
