PECTEN. Testa subrotunda, altera planior, basis transversa, anguli transversi (auriculæ) ad basin. Cardo cavitas conica, striis utrinque 3 longitudinalibus obliquis.
The genus OSTREUM, enlarged by the addition of the true oysters confounded with the Mytili, the Meleagrinæ, Aviculæ, and the Anomia placenta, was thus characterized:—
O. maxima. Pec. radiis 14 rotundatis longitudinaliter striatis.
In place of Gualtieri, "List. Ang. 184. t. 5. f. 29. Pecten maximus," and "Faun. Suec. 1343" were referred to: these synonyms had been added subsequently to the description.
O. Jacobæa. Pec. radiis 14 angulatis, fornicis longitudinaliter striatis.
The cited drawing of Gualtieri was not mentioned.
O. ziczac. Pec. radiis 18 explanatis.
No specific name was attached to this, the preceding, and the next two species.
O. striatula. Pec. radiis 16 obliteratis, transverse membranaceostriatis, margine integerrimo.
O. minuta. Pec. radiis 20 convexis.