e was at least a foot in length.

A number of black minute animals were caught, which, at a rapid glance,
looked not unlike fleas with long feelers or antennae.

We caught also this day an animal (Salpa) which consisted of a gelatinous
transparent bag, having an orifice provided with a valve that opened and
closed the orifice at pleasure; there was no other opening to the sac
that I could discover; I passed the end of a pencil down it, but although
it passed readily through the valve it could not at first pass through
the bottom of the gelatinous sac; but I afterwards found that this was an
error, and that the pencil could be passed right through the body of the
animal, which was provided with a valve at each end. I found also that
the united animals had the power of swimming with either end foremost.
There was an intestinal tube in the animal of a dark reddish brown
colour. This animal appeared to exist very badly alone, fourteen of them
were always found united together by a plane; they then formed a mass
shaped like half an orange and having a cup at its upper surface; the
intestinal canals, when they are in this position, are all brought near
to one another, and the whole mass looks not unlike a flower; they are
united to one another by so thick a fluid that it is very difficult to
separate them. If one or more are torn away from the mass the outside
ones immediately join together and form a united mass again, of the
original shape. They open the orifices at different times: that is, two
or three open theirs at the moment that some of the others are closing,
so that no regular or simultaneous movement takes place between the
different animals. This irregular movement of the animals gives to the
whole body an irregular rotatory motion; but when one is separated from
the others it can only drive itself round and round upon its own centre,
and has not the faculty of propelling itself as the other acalepha have.
They also swim with either end foremost, in the manner the other acalepha
do.

We saw also some animals of this class, and nearly as large as the ones I
have just described, but they differed in their form and mode of
attachment, and joined themselves in long strings, two deep, so as to
look like gelatinous snakes. I have before described animals of this
class with blue spots. I think that a good mode of classifying these
animals would be from their form of arrangement when united.

July 17. South latitude 19