Some forty years ago, Dr. Theodore Cantor, F.Z.S., devoted a good deal of time to the study of the pelagic serpents, and wrote a somewhat detailed account of them to the Zoological Society. His paper, published in the _Zoological Society Transactions_, 1842, vol. ii., was considered the most important that had as yet appeared. He, therefore, has been one of our first authorities. Subsequently we are indebted to Günther, Dr. E. Nicholson, Gerard Krefft, and Sir Joseph Fayrer for the results of their individual observations. In my foregoing descriptions I have culled from each of these, and as most modern writers on this subject merely reproduce from the works of Günther, Cantor, and Fayrer, I will keep chiefly to these in what further has to be said of sea snakes. First, they belong to the tropical seas of the Eastern hemisphere, and are most numerous in the Indian Ocean, where they abound. The geographical range of a few is, however, somewhat extensive, viz. from Madagascar and that part of the African coast to northern Australia, the Bay of Bengal, and even to the western coasts of Panama; while others are restricted to certain localities. All are highly venomous. They are wild and ferocious as well, and therefore peculiarly dangerous, and are the great dread of fishermen, who carefully avoid them. Accidents, nevertheless, frequently happen through their being caught in the nets, when, from their exceeding activity, it is difficult to disengage them and set them free again. When out of the water they try to bite at the nearest objects, and being dazzled by the light, strike wildly, unable to aim correctly. Cantor informs us that he has known them to turn and strike their own bodies in their rage, and that he has found difficulty in disengaging their fangs and teeth from their own flesh. Owing to the great danger attending their capture, and also the almost impossibility of keeping them alive when out of the sea, less is accurately known of the pelagic than most other snakes. Even if placed in a large hole in the ground filled with sea water, or a capacious tank similarly supplied, they die very rapidly. Sir Joseph Fayrer in his experiments resorted to every means in order to keep them alive, but informs us that their exceeding delicacy caused their rapid death in spite of the utmost care. Dr. Vincent Richards, however, has succeeded in keeping some alive several weeks. In length they vary from two to ten feet. Krefft says that the largest he ever saw was nine feet long. Günther states that they sometimes attain twelve feet, and sea snakes of even fourteen feet in length have been occasionally reported, though not perhaps from well authenticated sources. It is probable that, like all other reptiles, they attain their greatest proportions in the hottest regions.