Belonging to the genus of polypi is the animal known as the ozæna, being so called from the peculiarly strong smell exhaled by the head; in consequence of which, the murænæ pursue it with the greatest eagerness. The polypi keep themselves concealed for two months in the year; they do not live beyond two years, and always die of consumption. I must not omit here the observations which Lucullus, the proconsul of Bætica, made with reference to the polypus, and which Trebius Niger, one of his suite, has published. He says that it is remarkably fond of shell-fish, and that these, the moment that they feel themselves touched by it, close their valves, and cut off the feelers of the polypus, thus making a meal at the expense of the plunderer. Shell-fish are destitute of sight, as well as of all other sensations but those which warn them of hunger and the approach of danger. Hence the polypus lies in ambush till the fish opens its shell, immediately upon which, it places within it a small pebble, taking care, at the same time, to keep it from touching the body of the animal, lest, by making some movement, it should chance to eject it. Having made itself thus secure, it attacks its prey, and draws out the flesh, while the other tries to contract itself, but all in vain, in consequence of the separation of the shell, thus effected by the insertion of the wedge. So great is the instinctive shrewdness in animals that are otherwise quite remarkable for their lumpish stupidity. In addition to the above, the same author states, that no animal in existence is more dangerous for its powers of destroying a human being when in the water. Embracing his body, it counteracts his struggles, and draws him under with its feelers and its numerous suckers, when, as often is the case, it happens to make an attack upon a shipwrecked mariner or a child. If, however, the animal is turned over, it loses all its power; for when it is thrown upon the back, the arms open of themselves.