We caught also a new species of Janthina, the float of which, instead of being nearly round and extending over the shell on each side, was spread like a spiral fold from the shell; the breadth of this fold was 0.45 inch, close to the mouth of the shell, and it gradually tapered off to a point, its length being 3.6 inches.  This float being curved round like the tail of an animal, the whole thing bore the appearance of being a sort of snake, of which the shell was the head; the sailors called them caterpillars before I had examined them.  The float was composed of two parts, one of which was only froth and the other was apparently some extraneous substance attached to the froth.  The shell is very different from those of the other nautili in being much more deeply indented with circular striae.

July 18.  South latitude 19 degrees 49 minutes; west longitude 3 degrees 10 minutes 15 seconds.

We have lately caught several specimens of Creseis.  Each consists of a cylindrical tube, increasing in size from its broadest extremity to the centre where it is thickest, and decreasing from the centre to its other extremity, where it becomes a fine point.  It is throughout its extent gelatinous, transparent, and of strong consistency.

There is apparently a valve at its broadest extremity.

Length 1.1 inch. 
Breadth in centre 0.1 inch. 
Breadth at mouth of wide extremity 0.08 inch.

We have several times caught a triangular, transparent, gelatinous animal; it is 0.18 inch in thickness, and in the outer pulpy gelatinous mass there is an interior sac, and strong muscular bands are marked across this.  The sac is composed of three lobes, two of which have apparently no external opening, whilst at the end of the main lobe there is one which closes with a valve; through this I have seen them take in little animals, which reached no farther than the centre, from which the lobes radiate, when the sac became violently agitated, and made strong efforts to expel the foreign substance.  This animal was very sensitive, more particularly about the opening of the entrance.

We caught today the lower part of the species of Diphyes which we had found on the 13th November 1837, in 30 degrees 7 minutes south latitude, in the Indian Ocean.  This animal is thus distributed over a wide range.

We also found a very minute species of the animal similar to one which we caught on July 1st 1840.  Those we caught today were scarcely 0.05 inches in diameter.  They unfolded little wings and flew with them in precisely the way those did which I described on that day.

Nothing I have seen is more remarkable than the flight of these little animals; their wings are milk white and very large for their body, and as they fly, the ends, from their pliancy, bend over, which imparts to the motion a very graceful appearance; these wings are composed of a very fine membrane like that forming the wings of a bat.  At one time these little animals hovered over a single spot like a bird of prey in the air, flapping their wings in just the same manner.  At another time they darted forward with great rapidity, and the vibration of their wings was so rapid that I could not count them.  When folded up they look like very minute gelatinous animals with a black internal spot, but when touched their shell can be felt.  We saw a shoal of whales today.