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branchiata. In the female, moreover, the coxal plates are much more fully de-
veloped, forming together a broad continuous area flanking
the sides of the meso-
some. Also the appendages of the metasome are rather different, the lamellae
of the pleopoda being much smaller and perfectly smooth, whereas the uropoda
are quite unusually elongated.
Occurence. I have only seen 2 specimens of this form, the one ap-
parently adult, or nearly so, the other evidently not yet fully grown, having the
incubatory plates in process of formation. Both these specimens are figured on
the accompanying plates, in order to show the differences. The young specimen
has the body less asymetrical, and of a rather regular oval form, and the coxal
plates are also more regular, forming on both sides of the mesosome a quite
continuous row ; but otherwise the 2 specimens agree exactly. They were both
found in the branchial cavity of Galathea dispersa, Sp. Bate. Messr. Giard and
Bonnier record likewise a species of Pleurocrypta from the same host, naming
it P. Hendersoni; but, as no description or figure has been given, it is impossible
to state, if these 2 forms are identical or not. That the statement alone of the
host is quite insufficient for identifying the parasite, is clearly proved by the
fact, that one and the same species
of Crustacea not seldom is found to be in-
fested by several species of parasites, often belonging to very different genera
In the present case it may be mentioned, that a species of Pesudione, P. confusa
Norman, is recorded from the very same species
of Galathea.
3. Pleuroerypta microbranchiata, G. 0. Sars, n. sp.
(PL LXXXVII, fig. 2).
Specific Characters. Body of female broadly oval, rather asymetrical,
being twisted to the right or left hand, according to its place
phalon of moderate size, frontal edge slightly curved,
on the host. Ce-
lateral corners obtuse.
Segments of mesosome well defined, with the lateral parts slightly elevated ; coxal
plates less
fully developed than in the 2 preceding species. Epimeral plates
of metasome discontiguous, lanceolate. Eyes distinct. Antennae, oral parts and
legs of the usual structure. Incubatory plates large, though somewhat apart in
the middle. Pleopoda comparatively small, with the lamellae perfectly smooth.
Uropoda of inconsiderable size, forming 2 small oblong lamellae. Male compara-
tively short and stout, depressed, oblong oval in form, with the greatest width
in de middle, metasome forming an undivided obtusely triangular piece. Colour