PINNA.
The definition was not precisely similar in words to that of the 'Systema,' but the sense varied but little. It ran as follows:—
Testa oblonga, membranaceo-fragilis, basi angustata. Cardo nullus, sed valvis altero latere coadunatis ut una appareat.
P. rudis. P. rugosa squamis fornicatis per seriem digestis.
The name of this shell, identified (I think wrongly) by our author with the one he had termed rudis in the 'Systema,' was originally fornicata.
P. nobilis. P. squamis canaliculato-tubulosis subimbricatis.
P. muricata. P. striata, squamis concavis ovatis acutis.
"List. Hist. t. 370. no. 215," and "Sloan. Hist. i. p. 254," were present among the original synonyms.
P. rotundata. P. squamis obsoletis, testæ margine rotundato.
P. saccata. P. nuda saccata erectiuscula.
P. digitiformis. P. nuda digitiformis incurva.
P. lobata. P. nuda lobata.
In addition to the printed species, an anomalous Pinna, which I doubt not was the Lingula anatina, is here described.
P. viridis. P. ovalis, basi compressa.
Generis dubii huc relata, donec certiora determinentur.
Testa utraque ovali-oblonga, viridis, intus magis pallida; quasi compressa, et fere naviculata, acutior.