y much more perfect. Each of its tentacula terminates in a
small feathering tip when it is in the water, like the little figures at
the side, and by the help of which they swim; these have a horny feel to
the touch, are destitute of smell, and look like a transparent scale when
they lie in your hand.

We also caught this day some little transparent shells (Cuvieria) of a
cylindrical form, and blunt at the end; they put out two little fins with
which they swam.

I was unfortunately too unwell this day to describe all the other
specimens we caught, which were numerous. The sea was full of small
acalepha, and in the midst of a shoal of these a whale was seen.

November 19. Latitude 25 degrees 50 minutes south; longitude 106 degrees
22 minutes east.

Birds first re-appeared again. I saw a large flock of two kinds, but was
not near enough to ascertain what they were. I have before noted the fact
that almost at the exact point where the southern birds of the family
Longipennes disappeared those sea-jellies (acalepha) which have the power
of stinging, began to show themselves; previously to our passing this
point I had not seen one: I saw several however today at no great
distance from this flock of birds.

We saw float by this afternoon one of the acalepha, apparently about two
feet long and shaped generally like a water snake; its tail had fins like
that of an eel, of a purplish tinge; I could distinctly see its head and
various vessels in its interior for it was quite transparent. We had no
net ready but threw a stick with a piece of string attached to it, the
string passed under it but in pulling up cut through it as though it had
been jelly.

Caught an animal (Cymothoa) shaped exactly like a woodlouse:

Length 0.4 inches.
Length of antennae 0.15 inches.
Breadth of body 0.12 inches.

It had six legs, and a tail-like fin behind on each side, and nine rings
on its back so that it could roll itself almost into a ball, these rings
extended no farther than from its head to within 0.12 inches of its
hinder extremity; colour very pale blue down the back, bright prussian
blue on each side; it crawled about when taken out of the water, and
lived for some time; its fins, or fin-like legs, when it thus crawled
about, were folded under its tail; eyes distinct.

MOLLUSCA.

November 20. Latitude 25 degrees 14 minutes south; longitude 106 degrees
49 minutes east.

A shell, Janthina exigua, was caught this evening, 8 hours