OSTREA. 115 
Ostrea foltunr. 
The Ostrea folium of Chemnitz (Conch. Cab. vol. vii. pl. 71, 
f. 662 to 666) has generally, and apparently with justice, been 
accepted as the representative of the Linnean species. Our 
author, who did not himself possess the shell, has, in his own 
copy of the ‘Systema,’ by changing “Re” to “ Ar,” corrected 
the erroneous reference to Regenfuss in his twelfth edition: 
naturalists, however, have not been misled by the typographical 
blunder, from the circumstance that twelve plates only by 
Regenfuss have ever been published. Klein’s engraving was 
copied from Rumphius. 
Ostrea orbiculacts. 
Our author did not possess this species, the characters of 
which one could almost fancy were drawn up solely from 
Gualtier’s figure. Assuredly they are utterly inadequate to 
ensure an identification of the species: hence no writer has yet 
succeeded in determining it: Chemnitz thought it was the shell 
he has delineated in plate 74, figure 680 of his ‘ Conchylien 
Cabinet,’ but that oyster, which I should conceive to be a 
mere variety of his O. plicata, has such evident folds that 
even Gualtier and Schroter, no severe critics, have queried its 
identity with the Linnean orbicularis. Some Ostree of my own 
cabinet, which I have every reason to believe else undescribed, 
taken from an Avicula supposed to inhabit the Red Sea (it was 
collected by Lord Valentia) correspond remarkably well with 
Gualtier’s figure. When adult, (these specimens are immature) 
it varies greatly in figure, often, indeed, it becomes elongated, 
but has invariably a brilliant green (not iridescent) interior, 
and scabrous granules (like those of frons) surrounding the 
margin of the superior valve. Had that shell been suggested 
by any previous writer as the representative of the Linnean 
species, I should have assented to the reasonableness of his 
recognition, as a probability: under existing circumstances, I 
feel, with Dillwyn, that the Ostrea orbicularis must ever be 
