_Planaria_, _Salpa vivipara Per._, a _Pyrosoma_, resembling
that of the Atlantic, and a _Lepas_, attached to the shell of the
_Janthina_. Our collection of Acalephi was extremely rich; of fourteen
kinds taken, only one, _Physalia Lamartinieri_, was known to us.

Our eight days' stay at the coral island Otdia, afforded us an
opportunity to observe or collect about one hundred different kinds of
marine animals. It has already been mentioned elsewhere, that the only
kind of mammalia found upon this island is a middling-sized cat, which
feeds on the fruit of the pandanus tree, and makes its nest in the dead
branches, which it easily hollows out. Several lizards have also been
found in these islands, such as the striped _Ablepharus_ of O Tahaiti,
and a small _Gecko_; a large coal-black lizard was several times seen,
but always escaped among the dry pandanus leaves. The fishes are
remarkable for the singularity of their form, and the beauty of their
colours; those brought to us by the inhabitants belonged to the
_Holocentrus_, _Scarus_, _Mullus_, _Chaetodon_, _Heniochus_,
_Amphacanthus_, _Theutis_, and _Fistularia_.

Of Crustacea we saw twenty different kinds; among them a _Gonoplax_ of
the middling size, and as white as the coral-sand, among which it lives,
on the shore. The _Hippopus_ found here differs from the _maculatus_
already known by the much greater elevation of its shell. The large
_Tridachna_ is the _Tr. squamosa Lam._ It is very unusual to meet with
an animal belonging to the family of Lepades in tubular holes made in
the coral rocks, as is the case with the _Lithonaetta N._ Among the
twenty kinds of tabular coral here observed, there was not one of those
collected at O Tahaiti; there were three new _Distichoporae_,
_Seriatipora_, six kinds of _Madrepora_, two _Porites_, four _Astrea_,
_Pocillopora caerulea_, and another kind, forming broad, yellow, leafy
masses, the slime of which stings like a nettle; _Cariophyllaea
glabrescens Cham._, and _Tubipora_, with red animalculae.

A calm of several days, between eighteen and twenty degrees of north
latitude, during our passage to Kamtschatka, afforded opportunities for
the observation of several remarkable animals. A small animal of
Lamarck's family of Heteropodes, with two rows of separate fins,
received the name _Tomopteris_. Secondly, a _Salpa_, of the class which
lives apart and has fine long fibres projecting from the hinder part of
the body. Thirdly, a small