a 
we 
LL 
S. Canpipus Remeri.—S. Srrieiratus. Turton. 
B. p. 97, t. 6. f. 13.— Mart. f. 43.—F. p. 439.— 
Elongated oblong, breadth twice and a half the length, 
ends rounded, uniform white, marked with coarse ridges 
of growth, and anteriorly with curved radiating strigils ; 
beaks subcentral, anterior slope with divaricating striz ; 
ventral edge straightish, subincurved in the middle ; 
an oblique and erect tooth in each valve (in one valve 
the former rudimentary ) nymphe distinct. 0,80..,1,6. 
Cornwall. 
S. Scoputa.—Psam. Scopuna. Turt. B. p. 98. ¢. 
6. f. 11, 2.—L. p. 439.—Kidney-shaped, subequila- 
teral, oblong, glossy white, ventral edge strongly incur- 
ved in the middle, striated in two directions anteriorly 
(oblique striz not more than 20.): all the teeth erect. 
2,...2. Hxmouth. 
GrENus.—PANOPEA. 
Equivalve,transverse, unequally gaping at the ridges, 
a conical cardinal tooth in each valve, and on one 
side a short ascending compressed, not exserted 
callus. Ligament external, fixed on the callosities. 
P. Arctica. Deshayes.—GuycimerRts. A. Lam. 2. 
—PcuHiycimeRIs. Bean in Mag. N. H. 8. f.51. p. 
503.—White under a yellowish wrinkled epidermis, 
