Back when mythical lasses of the sea weren't so mythical....

In St. George Jackson Mivart's "Types of Animal Life," we see that the primary categories have apparently changed drastically since 1893, as the book's contents cover "Monkeys; Opossum; Turkey; Bullfrog; Rattlesnake; Serotine or Carolina bat; American bison; Raccoon; Sloth; Sea-lions; Whales and mermaids; The other beasts."