126 
NATICA sigaretina. 
TAB. CCCCLXXIX.-- -fig. 3. 
Spec. Char. Much depressed; umbilicus large,, 
filled with a lenticular callus. 
Syn. Natica sigaretina. De France , MSS. 
Spire small and indistinct, almost concealed by the last 
whorl ; the aperture is ovate, curved and pointed above : 
an oval compressed callus fills the umbilicus ; but as the 
shell increases the callus rises faster than it fills the 
hollow, so that a portion is generally open for a small 
depth. 
From a mass of Sandy Marl belonging to the Lon- 
don Clay; but found among alluvium in Suffolk, by 
Dawson Turner, Esq. many years ago : the same spe- 
cies has been presented by Mons. De France, named as 
above, found near Bordeaux. 
TAB. CCCCLXXIX.- -fig. 4. 
This Figure represents a magnificent specimen of Na- 
tica glaucinoides of M. C. tab. 5. It is from the Suffolk 
Crag, and belongs to the Rev. G. R. Leathes, to whose 
kindness we are much indebted. 
The same species is often found smaller at Bra- 
merton and in other parts of the Norfolk and Suffolk 
Crag, it is probabN the Nerita helicina of Brocchi, 
297, tab. 1, f. 10. 
