During a calm, by which we were detained two days on the Portuguese coast, _Janthina fragilis_ and _exigua_, _Rhizophysa filiformis_, and another species, were brought up. Many specimens of the _Janthina exigua_ were found, the bladder-like mass of which was stretched out to a great length, and bent into the form of a hook at the end. On the outer side was observed a fleshy streak, bordered by a close row of small paunches: these paunches, which were externally open, contained a great quantity of brown atoms, apparently spawn, and evidently in motion. With respect to the _Rhizophysae_, it has been discovered that they are of the same genus as the _Physsophora_, the hard part being torn away in the act of catching them; upon this occasion also, several of these separated parts, still in motion, and bearing some resemblance to salpas, were brought up, and accurately examined. Off the Cape de Verd Islands, in addition to the _Exocoetus volitans_, which abounds there, various specimens of the much larger _Exocoetus exsiliens_ of Cuvier alighted on board our vessel. The latter species is distinguished by the long black fins of the belly, and by its remarkably large eyes, differing greatly from the species described by Gmelin under the same denomination. The calms near the Equator afford an abundant harvest to the zoologist, the tranquil water presenting an immense variety of marine animals to his view, and allowing him to take them with little trouble in a net. The open woollen stuff used for flags offers the most convenient material for making these nets, as it allows the water to run through very quickly, and does not stick together. A short, wide bag should be made of this stuff, which may be stretched upon the hoop of a cask, and the whole fastened to a long, light pole. From the height on which we stand above the water, it is impossible to perceive the smaller animals; the best way therefore to catch these is, to hold the net half in the water, as if to skim off the bubbles of foam from the surface; then, after a few minutes, if the net is drawn out, and the interior rinsed in a glass of fresh sea-water, one may frequently have the pleasure of seeing little animals of strange forms swimming in the glass. In the course of ten days, I obtained, in this way, thirty-one different species of animals, among which was a small _Diodon_, eight small crustacea of forms almost wholly unknown; a sea-bug (_Halobates micans_); three species of Pteropodes, closely allied to the _Cliodora_; a small and remarkable Hyaloea; two new _Janthinae_; _Firola hyalina_, _Pyrosoma atlanticum_, _Salpa coerulescens_, and another unknown; _Porpita glandifera_, and a new species of globular form; a _Velella_; two new species of Acalephes, of the same family as the _Diphyes_; and further _Pelagia panopyra_, and two other very small species. When the sea was a little agitated on the Brazilian coast, we frequently saw the