34 THE MOLLUSCA OF THE FIRTH OF CLYDE. 
British distribution Everywhere throughout our seas in 
sandy bays; a very common shell. 
Foreign localities—From Norway (Lovén and others) to 
Spain, Portugal, Mogador, and Canaries (?) (M‘Andrew), and 
throughout the Mediterranean, reaching to the Black Sea 
(Middendorf). 
LuTraria, Lamarck. 
* Lutraria elliptica, Lamarck. 
Mactra lutraria, Linné; Chama magna, Da Costa ; Concha 
longa, ete., Lister; Lutraria vulgaris, Fleming. 
Habitat.——At lowest ebb of spring tides in soft oozy sand ; 
gregarious and common, especially at the head of deep bays 
and lochs, where much soft sand and mud have accumulated. 
I have taken it in Rothesay, Kamesburgh, and Ettrick 
Bays, Bute; Fintry Bay, Cumbrae ; and at the Trench Point 
and the Lochend, Campbeltown Loch. At all these locali- 
ties fine specimens may be obtained, but only at low spring 
tides. 
In spite of the uninviting appearance of this molluse and 
the dirty ground it inhabits, the fishermen at Cumbrae 
(who know it by the local name of “ Onion”) assure me that 
it is excellent eating, being rich and tender. Its principal 
use, however, is for bait. Lister figures it, but does not 
record its gastronomic value. 
British distribution.—Throughout our coasts wherever 
suitable conditions exist. 
Foreign localities—From Norway to Holland, France, 
Spain, Portugal, and on both sides of the western part of the 
Mediterranean and in the Adriatic. 
SCROBICULARIA, Schumacher. 
« Scrobicularia prismatica, Montagu. 
Ligula prismatica, Montagu ; Mya prismatica, Turton ; 
Amphidesma prismatica, Brown ; Syndosmya prismatica, 
Forbes and Hanley. 
Habitat-—In muddy sand in 6 fathoms of water off 
Ardrishaig Pier, rather common. This is the only locality 
in which I have taken it in any number; only young 
shells, however, were got. A few were obtained alive at 
Lochgoilhead, and some single valves in Rothesay Bay. It 
is probably a very local species in this district. 
