69 
TEREBRATULA hemisphaerica. 
TAB. DXXXYI. —jig. 1. 
Spec. Char. Hemisphaerical with a produced in- 
curved beak, longitudinally striated ; striae very 
numerous. 
The lesser valve of this is nearly flat ; it is a little un- 
dulated : the striae are in fact minute plaits, and give a 
finely toothed margin to the valves, which is otherwise 
even. 
Found at Ancliffe. We are indebted to the cabinet of 
the Rev. G. Cookson for it. 
TEREBRATULA rigida. 
TAB. DXXXYI. —Jig. 2. 
Spec. Char. Orbicular, plaited ; plaits granulated, 
increasing in number towards the margin ; 
lesser valve nearly flat, the other convex, with 
a small beik. 
A well-defined species, with an even front and small 
circular aperture in the beak. 
Only one specimen of this little shell has come with- 
in our observation : it was found in the Chalk near 
Norwich. 
TEREBRATULA striatula. 
TAB. DXXXYI.— 3, 4 # 5. 
Spec. Char. Imperfectly bilobate, compressed, lon- 
gitudinally ovate and striated; front truncated, 
sometimes with a sinus ; striae granulated, re- 
peatedly forked. 
Syn. Terebratula striatula. Mantell , GeoL Sussex , 
p. 131. tab . 25. Jigs. 7, 8, 8$ 12. 
Both valves of this Terebratula have generally a lon- 
gitudinal depression near the front, although some spe- 
