3.  They have no means of warming themselves by exercise or motion.

4.  The species of food which they subsist on is confined to the latitudes in which they themselves live.

5.  They would have to traverse great distances in ungenial climes, and contend against adverse winds, the children of placid seas and genial suns hurried into giant waves and chilling storms.

6.  It is not probable that they are swept along in currents, from the circumstance that in the one which flows along the coast to the eastward of the Cape we could find none of them, whilst upon its very edge they were in abundance.

Could however their eggs be swept along by a current, and after having been wave-tossed for months or years, be at last borne into waters sufficiently warm to hatch them, and the animals, finding themselves in a genial climate, have increased and multiplied?

The numerous little animals of the species which I have always considered to be the Velella of Lamarck went sailing merrily by us today; the least breath of wind made them turn round and round; and this was their mode of progression, the animal moved its little sail which I have before mentioned, and worked its tentaculae so vigorously as to make ripples in the water, in the midst of which it went buoyantly floating along.

Caught another fish (Stenopteryx Illustration 5) of the same species as that found on the 15th of July.  The accompanying figure is drawn from minute measurements.  The length of this specimen was 2.5 inches, its thickness through the thickest part 0.38.

What I had before imagined to be either a spine or fin turned out to be a pectoral fin.

It thus has two pectoral, one dorsal, and one ventral fin, properly speaking; but the greater part of the body is surrounded by some cartilaginous substance which it probably uses as a fin; under the line b c there is a curved portion of this matter, and above and attached to the fish is a line of round white silvery scales, about ten in number.

Between a and b there is another curved mass of transparent cartilaginous substance, along the bottom of which runs a spine to which is attached a fringe-like fin.  There is a spine upon the back; the eye is very prominent and bright; upon the back, between the eye and the spine, there are successive stripes of purple and burnished gold, so that this little animal is one of the most gorgeously coloured denizens of the ocean.  It swims about amongst the purple barnacles and pink nautili, seeking on the shores of these shining islands its prey, the curious formation of its mouth being admirably adapted to enable it, whilst swimming under these painted floating islands, to crop off what it lists.

There were scarcely any gelatinous animals in the sea this day; but many Janthina shells and Velella were round the ship, to which were attached barnacles of different species; amongst this group of islands numerous crabs were swimming about and running over them.  Animals resembling a wood-louse were also in the sea, swimming and running about the floating shells and barnacles.