Note 2605 — BOOK IX. THE NATURAL HISTORY OF FISHES.
John Bostock translation
Probably some of the Cypræa; which have been already alluded to in Note 6 to c. 41 of the present Book. Cuvier remarks, that there are many of the univalve shell-fish that float on the surface of the water, but none, with the exception of the argonauta or nautilus, are known to employ a membranous sail.