Caught also two minute animals resembling a species of shrimp (Penaeus); colour of both pale blue.  The tail of the largest when examined in a microscope precisely resembled in appearance the fin of a fish.  I did not examine the smaller one.  Dimensions of the largest: 

Total length 0.2 inches. 
Length of feelers 0.15 inches.

Of smallest: 

Total length 0.13 inches.

When put into eau-de-cologne these animals changed to a pink colour.

June 17.  South latitude 29 degrees 19 minutes; east longitude 40 degrees 19 minutes.

Caught a specimen of Glaucus.

Total length 0.35 inches.

Colour down the back deep indigo blue; stomach bluish white; sides bluish white (silvery) like a frog; tail tapering to a point; its head resembled that of a frog, and when out of the water it sat on its tentaculae, and raised its head and the fore part of its body, moving its head (a) from side to side; the tentaculae were all so delicate that they fell off, it had apparently eight on each extremity; it belonged to the same family as the animal I caught on the 14th of November 1837, in south latitude 29 degrees 26 minutes; east longitude 101 degrees 32 minutes.*

(Footnote.  See Illustration 10 volume 1.)

June 23.  South latitude 32 degrees 53 minutes; east longitude 29 degrees 45 minutes 15 seconds.

We for the first time saw Cape Pigeons and the Albatross.

June 27. ) South latitude 35 degrees 41 minutes; east longitude 25 degrees 13 minutes 20.  June 28. ) South latitude 35 degrees 15 minutes; east longitude 23 degrees 26 minutes.

Upon these two days we were in a rapid current, which we entered on the morning of the 27th, and on neither could we see the slightest signs of any of the acalepha class; but on the 29th, on which day we experienced no current, we found the greatest abundance of these animals; it appeared as if they had collected in large quantities at the edges of the current; and on the western side of it we found many animals which I had not seen on the opposite one.

June 29.  South latitude 35 degrees 31 minutes; east longitude 22 degrees 20 minutes 30 seconds.

The specimens caught were a minute fish, 0.35 inch in length; colour, back and upper half of sides, deep indigo; belly and lower half of sides, silver colour.  Also two sorts of barnacles (Anatifa) which I got near the side of the vessel.

We caught today a great number of the animals (Glaucus) I have mentioned above as having been taken on the 17th of June, as well as on other occasions.  I observed these animals in the water, and found that their long silk-like antennae had, when uninjured, a length of five or six inches; they swim with the rounded part first, and the long antennae trailing after them like tails; the progressive motion is produced by introducing water into certain sacs, or cavities, and expelling it by a contraction of the muscles with great violence.  I observed their motions from a boat at first, and afterwards when they were in a glass of water.  I counted the number of times they expelled water in a given time when swimming, and found the mean of several observations by a chronometer to give ten strokes in twelve and a half seconds.