348 GINGLYMACONCHA. OSTREADZ. 
dredging in the Frith of Forth, and observed a single specimen 
in the collection of Dr. Fleming, which I believe was found in 
Shetland. 
I am obliged to change the name fragilis, as it has been 
before employed in this genus. 
3. LIMA TENUIS. 
Shells smooth, pellucid, concentrically striolated, and with 
very fine vertical elevated lines, placed far apart from one 
another ; the epidermis whitish. 
I obtained two single valves of this species, which were 
dredged up at Newhaven, in the Frith of Forth. 
4. LIMA UNICOSTATA. 
Shells pellucid, with vertically elevated lines; one of the 
middle lines is elevated and forms a rib; both valves imme- 
diately under the rib are channeled ; the epidermis white. 
Pecten subauriculatus, Mont. Test. Brit. Supp. 63; Flem. 
Edinb. Encycl. vir. 98. 
Ostrea subauriculata, Turt. Conch. Dict. 131. 
This species occurs, but very rarely, in deep water in sandy 
bottoms. 
Had I not seen the specimen in Montagu’s collection ticketed 
by himself, it would have been impossible for me to have made 
it out either from his figure or description. 
Mr. J. Cranch has occasionally procured it for me from the 
trawlers on the coast of Devon, in very good condition ; and 
Dr. Goodall, the Provost of Eton, has detected young speci- 
mens in sand, from Padstow Harbour in Cornwall. 
FAMILY III. OSTREADA. 
Shells inequivalve ; the right valve flattened; both valves 
entire; the hinge straight ; the ligament nearly internal. 
