148 
TEREBRATULA variabilis. 
TAB. DLXXVI.—figs. 2—5. 
Srec. Cuar. Orbicular or oblong, very convex, 
smooth ; the beak of the larger valve pro- 
duced, truncated, with a round perforation. 
” 
Aways very convex, but varying in shape from oblong 
oval to orbicular: the beak is large, straight, and trun- 
cated deeply; the area within it is convex, with a large 
‘sinus. 
A very abundant fossil in the Crag; but the valves 
are never found joined, and are always much worn. 
Figs. 2. and 4. are from specimens collected by our 
zealous geological friend Mrs. Murchison. | 
