30 
NERITA aperta, 
TAB. CCCCXXIV.— 2, 3 and 4. 
Spec. Char. Sub-hemisphaerical, smooth ; 
spire visible, depressed ; aperture orbicular, 
expanded; inner lip obscurely crenated, 
bearing one large tooth. 
A. thickening of the outer lip a little 'within its sharp 
edge, together with its general form not being produced 
in the middle as in many Neritinae, seem to warrant the 
placing this as a Nerita. In most specimens the surface is 
marked with acutely zigzag brown lines of width equal 
with the white between them : but one individual has a 
black ground, with oval white spots. (See fig. 4.) 
Professor Sedgwick discovered this in Colwell Bay, 
on the Isle of Wight ; from his specimens we have taken 
figures 3 and 4, while fig. 2 is from a Barton example that 
we have just received from our kind friend Miss Salisbury. 
The Isle of Wight specimens are often much corroded. 
