124 
oblong, irregularly sinuous at the margin on the sides, 
with numerous extremely fine radiating stvize only visible 
towards the margin, the dorsal portion being sculptured 
by numerous regular transverse ones; hinge pointed, 
terminal; outside silvery, under the hinge a large 
hollow vaulted chamber which is much curved on one 
side and scaly on the outside; perforation round and 
nearly closed 12. Torbay. 
A. Tupuraris. Turt. B. p. 234.—F. p. 396.— 
Orbicular, whitish, with the beaks terminal ; perforation 
entire all round and produced into a raised cylindrical 
tube. 4. Attached to Fuct. 
A. Coronata. Bean in Mag. N. H. 8. p. 564. f. 
52.—Oval, glossy, pale amber, the upper valve concave, 
smooth, with rather an undulating surface ; beaks 
pointed, not terminal, above which are three or four 
rows of spines the outer extending beyond the shell 
giving it a coronated appearance ; under valve convex, 
with an irregular surface and a few indistinct traces of 
longitudinal strie. 3...3. Scarborough. 
TrispE.—RUDISTA. 
Ligament, if any, undiscovered, or represented by a 
tendinous cord which attaches the shell. 
