Only one of these ribs was, at times, affected at the same moment, so that they appeared each to be capable of an independent movement.
We caught also many small insects, and some shrimp-like animals.
The sea was full of some things resembling hairs, but which broke the moment they were touched.
On this evening we placed a large number of acalepha in a bucket, and on agitating the water it became a mass of phosphorescent light.

It is strange that these animals should never emit this light without being irritated.
July 1.

South latitude 35 degrees 51 minutes; east longitude 18 degrees 56 minutes; average temperature of water, 65 degrees.
This day many specimens of different kinds were taken; and amongst them a shellfish (Hyalea) the same as that caught on the 13th November 1837, in south latitude 30 degrees 7 minutes; east longitude 100 degrees 50 minutes 10 seconds.

This fish today put out the apparatus with which it swam.

It consisted of two broad transparent wings, shaped like the first pair of wings of a butterfly, and which it moved in a precisely similar manner.