BRITISH OYSTERS : OLD AND NEW. 
213 
make it a living French oyster. Locard (Prodrome 1886, p. 
578) mentions 0 . obesa as a French species which is later on given 
by him as a synonym of 0 . stentina. 
OSTREA CANVEYENSIS , sp. nov. 
Mr. Spurred (Arch. Journ., vol. xlii., p. 1885), referring to 
the quantities of oysters on the margin of the Thames Estuary, 
mentions a shell bank on the eastern spit of Canvey Island. A 
small series which I have had sent me from that locality exhibit 
certain features which ally them to the small Mexican shell 
0 . mexicana, Sav. (Reeve op. cit., pi. xvi.),with which, fig. 35, 
they have much in common,and in less degree to the hollow-beaked 
Ostrea cucullata group. The shells are small, as if stunted, full 
grown, and very irregular in outline, and are all more or less 
attached by the under valve, which is the longest and, so far as 
exposed, coarsely corrugated. Upper valve flat or slightly ovate, 
beaks prominent, hollowed under hinge. Colour dead white 
striped with purple, margins deeply dentellated and coloured. 
My largest example measures length 75 mm. by breadth 50 mm. 
A solitary example that I obtained from Foulness measured 
95 mm. by 70 mm. The interior is white with a coloured scar 
(plate xvii., fig. 24). 
OSTREA ADRIATIC A Lamarck. 
My attention was called many years ago by Messrs. Etheridge 
and Bennie to a marine deposit at Cocklemill Burn, on the shores 
of Largo Bay, in Fife (for details see “ Marine Accumulation 
Largo Bay, &c.,” Proc. Roy. Phys. Soc., Edinburgh, 1890, 1893), 
which has yielded, besides other organisms, 155 species of 
shells. 13% of these are not known as inhabitants of the recent 
Firth of Forth. Since then I obtained at Mr. Damon’s sale, 
amongst others, a group of oysters of very irregular shape and 
proportion as compared with any other known in these islands, 
including the name shell 0 . adriatica as figured in the Moll, d'u 
Roussillon, pl.ii., figs 5 and 6, and its varieties alata and falcata 
both figured by Monterosato, op. cit., pi. ii., figs. 1-4. 
The Scotch shells are more or less corrugated and the surface 
is very irregular. The upper valve is plain, immediately fol¬ 
lowing the contour of the under valve, but leaving a deep breadth 
of margin strongly crenulate at the hinge area. Apex acute. 
