MARINE UNIVALVES 157 
shell are most common on the coast of southern 
California. 
Figure 140 represents the 
shell of the rare and beautiful 
Pleurotoma carpenteriana, 
Gabb, Carpenter’s Notched- 
side, (Sureula carpenteriana) 
This shell is spindle-shaped, 
with a conical spire, which 
slopes with the utmost grace to 
the apex, a long aperture, and 
an outer lip which has the 
characteristic notch near its 
junction with the whorl. The 
shell is marked 
with many fine 
lines of growth, 
each of which 
retains the pecu- 
liar notch. The oe ne 
color is reddish yellow, which 
is set off by numerous narrow, re- 
volving stripes of reddish brown. 
The length of a good sized specimen 
is three inches. This species lives 
off the coast of California, and most 
of the specimens have been obtained 
by dredging. 
Migure 141 gives us a magnified 
Fig- 41, x2) view of the shell of Pleurdtoma per- 
versa, Gabb, the Perverse Notch-side. It is called 
perverse, because the whorls revolve from left to 
