He might indeed not have been ignorant of the fallacy of the fable, but exploited it with narrative license to dramatize the desired imagery. Neither mussels nor barnacles would occur on furniture, however, unless permanently or periodically submerged under water. Snails could well be found on furniture under highly humid condition, but they do not occur on sea turtles. Presumably Melville had in mind one of the New England species of Clemmys , possibly C. Insculpta, which is famed for its intricately ridged carapace. At the time Melville wrote, the Galapagos tortoises were still being exploited by whaling vessels for long-lasting fresh meat.
Snakes are relatively well represented, although only two specific kinds are mentioned.
Surprisingly, the anaconda is one, the word occurring three times. Boas do not occur in Africa, but pythons do and presumably that is what Melville meant. Melville argued for several pages that St. George but encountered a crawling reptile of the land, instead of doing battle with the great monster of the deep. He did not explain how this might have been done on horseback.