u
_Klossia e._ seu _octopiana_), parasitic in _Sepia_, which is tri- or
tetra-zoic; and _E. octopianum_ (Schn.), (syn. _Benedenia_ seu
_Klossia o._) from _Octopus_, which is polyzoic, having 10 to 12
sporozoites. In both forms cysts containing megaspores and
megasporozoites, and others containing microspores and
microsporozoites are found, considered as representing sexual
differentiation thrown back to the very earliest stages of the
life-cycle.

Quite recently much additional light has been thrown upon our
knowledge of these parasites, including a new one, _E. jacquemeti_.
Moroff (1906) has shown that not one but many megagametes are formed,
and fertilized by the microgametes. For this reason he regards them as
Gregarines rather than Coccidia. Further, Leger and Duboscq (1906)
have found that the characteristic coelomic parasites (_Aggregata_) of
Crustacea, generally regarded as gymnosporous Gregarines (i.e.
Gregarines in which the sporozoites are naked) constitute in reality
nothing more or less than a schizogonous generation of these
Cephalopodan parasites, which have thus an alternation of true hosts.
The ripe sporocysts from the Cephalopod are eaten by a particular crab
(e.g. _Portunus_ or _Inachus_, according to the parasite), the
sporozoites are liberated and traverse the mucous membrane of the
intestine, coming to rest in the surrounding lymphatic layer. Here a
large "cyst" is formed, projecting into the body-cavity, the contents
of which give rise to a great number of merozoites. On the crab being
devoured by the right species of Cephalopod, the merozoites doubtless
give rise to the sexual generation again.

As the name _Aggregata_ is much the older, and as, moreover, there is
no longer any reason to retain that of _Eucoccidium_, these parasites
must in future receive the former generic appellation. With regard to
the various specific names, however, they remain quite unsettled until
the life-history is properly worked out in different cases (see also
GREGARINES).

It seems to the writer a much more open question than Moroff and Leger
and Duboscq apparently suppose, whether these parasites are to be
relegated to the Gregarines. For undoubtedly they have many Coccidian
features, and on the other hand they differ in many ways from
Gregarines. The chief feature of agreement with the latter order is
the possession of many female gamete