118 
NUCULA impressa. 
TAB. CCCCLXXY .—Jig. 3. 
Spec. Char. Transversely oval, depressed, smooth ; 
beaks near one extremity ; lunette deeply 
sunk, convex, elongated ; edges entire. 
The deep lunette, and margin regularly curved, except 
where the lunette makes it straight, sufficiently distin- 
guish this species. 
A silicized fossil from Blackdown. 
NUCULA antiquata. 
TAB. CCCCLXXY.— ^g. 4. 
Spec. Char. Triangular, rounded, gibbose, an- 
tiquated, longitudinally striated; lunette heart- 
shaped, sunk ; margin toothed. 
A more gibbose shell than most of the analogous Nu- 
culae : it is rendered very uneven by its irregular mode 
of growth ; the beaks are incurved and close together. 
From Blackdown, cast in Silex. 
NUCULA Ovum. 
TAB. CCCCLXXVI— /g. 1. 
Spec. Char. Transversely obovate, ventricose, 
smooth, anteriorly pointed. 
About the size of a wren’s egg ; nearly as deep as 
long ; the posterior extremity is regularly rounded, the 
other drawn out in a short point. 
Presented by our kind friend the Right Hon. the 
