OSTREADJS. OYSTER. 149 



the Republic of Venice. In the ' Intellectual Observer/ 

 vol. i., p. 483, is an account of an " oyster-shell " island, 

 by M. Aucapitaine, on the east coast of Corsica, com- 

 posed of layers of shells, bearing some resemblance to 

 the shell-mounds of St. Michel-en-l'tlerm, in La Vendee. 

 This island is formed of still-living species, and is 

 between three hundred and four hundred yards in 

 circumference, the greatest elevation about thirty 

 yards, and the mean elevation rather more than two 

 yards above the level of the sea. The Romans are said 

 by the fishermen to have deposited the shells of the 

 oysters there, which they salted for exportation, but 

 M. Aucapitaine does not believe in the artificial origin 

 of this island. 



According to M. de Quatrefages, the shell-mounds 

 of St. Michel-en-1'Herm are composed of oyster, mussel, 

 and scallop shells, of the same species as those living 

 now in the neighbouring seas. Many of them have 

 their valves still connected by the ligament which forms 

 the hinge, and they have not even changed colour. 

 The three banks of St. Michel- en-1'Herm are about 

 seven hundred and thirty yards in length, three hundred 

 in width, and rise about ten to fifteen yards above the 

 level of the surrounding marshes. 



Mr. Buckland mentions a large heap of oyster-shells 

 in G-alway Bay, at a place called Creggauns ; another 

 south-west of Tyrone, and one at Ardfry Point. The 

 Creggauns heap consists principally of the shells of the 

 oyster, mussel, and common cockle, though the whelk, 

 Peden varius, periwinkle, limpet, Nassa reticulata, 

 Helix nemoralis, Trochus,&nd Venerupis decussata (Tapes 

 decutsata ?) , are also found in it. There are layers of 

 wood-ashes and stones, apparently used as hearth- 



