Pliny tells us, that, in his time, after the diamonds of India and Arabia, pearls were esteemed most precious, and that we may be under no error as to the application of the text to the pearls found in shells, he further adds, that he had before spoken of these pearls in his book that treats upon the productions of the sea[1]. The diamonds in those times were so scarce, and esteemed so highly, as to be little known, except among princes, the smaller and most inferior kinds alone excepted. The pearls were the most costly jewels employed in the ornaments for the ears, the neck, and fingers of the fair sex, and the shells themselves were converted into various articles of finery for their wardrobe and furniture. But it is not, as before observed, within our province in this place, to enter into any such latitude of explanation as an ample illustration of these remarks may be conceived to merit. It is our object only to express ourselves in general terms: it may be sufficient therefore to observe, that among the luxuries of the great in the times of Pliny, Oppian, and Juvenal, it is certain they indulged their peculiar taste in the study of these productions of the deep. They not only amassed together the more curious among those shells whose beauty attracted their regard, they entered also to some extent into their history and manners, and were sufficiently informed as to their natural properties to render them subservient to the general purposes of luxury and life. They knew the distinctions between the land, the fresh-water, and the marine tribes of shells, and they proceeded with minuteness and sometimes fully into their history. No classic reader of the Halieutics of Oppian will doubt the general acquaintance of the ancients with those beings in their native element, nor will any one imagine, who is conversant with the lives of the philosophers of the infant ages of the world, that the study of Conchology, even as a science, was unknown. So many writings of the ancients, even of the classic ages of Greece and Rome, have disappeared, that it may be now impossible to form any very accurate conclusions, at the same time that enough remains to justify our persuasion that it was far from inconsiderable. Among others, the works of Aristotle, the preceptor of the Macedonian conqueror Alexander, have survived the ravages of time, and very happily, for the history of human knowledge unfolds to us the views which the ancients had then taken of natural science, and among the rest of the science of Conchology; and there is, moreover, every reason to believe that in the classification of the testaceous tribes, or shells, which the writings of this philosopher present us, we, in reality, possess the arrangement of the shells composing the Conchological collection of that most potent monarch, the conqueror of the world:—the classical distribution of the shells of the great Alexander, as they were disposed by the most