Having now completed our exposition of the properties which belong to the aquatic productions, it would appear by no means foreign to my purpose to give a list of the various animated beings which inhabit the seas; so many as these are in number, of such vast extent, and not only making their way into the interior of the land to a distance of so many miles, but also surrounding the exterior of it to an extent almost equal to that of the world itself. These animals, it is generally considered, embrace one hundred and seventy-six different[429] species, and it will be my object to set them forth, each by its distinct name, a thing that cannot possibly be done in reference to the terrestrial animals and the birds. For, in fact, we are by no means acquainted with all the wild beasts or all the birds that are to be found in India, Æthiopia, Scythia, or the desert regions of the earth; and even of man himself there are numerous varieties, which as yet we have been unable[430] to make ourselves acquainted with. In addition, too, to the various countries above mentioned, we have Taprobane[431] and other isles of the Ocean, about which so many fabulous stories are related. Surely then, every one must allow that it is quite impossible to comprise every species of animal in one general view for the information of mankind. And yet, by Hercules! in the sea and in the Ocean, vast as it is, there exists nothing that is unknown to us,[432] and, a truly marvellous fact, it is with those things which Nature has concealed in the deep that we are the best acquainted! To begin then with the monsters[433] that are found in this element. We here find sea-trees,[434] physeters,[435] balænæ,[436] pistrices,[437] tritons,[438] nereids,[439] elephants,[440] the creatures known as sea-men,[441] sea-wheels,[442] orcæ,[443] sea-rams,[444] musculi,[445] other fish too with the form of rams,[446] dolphins,[447] sea-calves,[448] so celebrated by Homer,[449] tortoises[450] to minister to our luxury, and beavers, so extensively employed in medicine,[451] to which class belongs the otter,[452] an animal which we nowhere find frequenting the sea, it being only of the marine animals that we are speaking. There are dog-fish,[453] also, drinones,[454] cornutæ,[455] swordfish,[456] saw-fish,[457] hippopotami[458] and crocodiles,[459] common to the sea, the land, and the rivers; tunnies[460] also, thynnides, siluri,[461] coracini,[462] and perch,[463] common to the sea only and to rivers.