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at least there seem to be no facts tbat are definitely against it. A greater number of joints
do not appear in any forms; a two-jointed protopodite and a three-jointed endopodite occur
in the most widely separated groups viz: Cypridinids, Halocyprids, C’yprids,
Nesideids, Cytheri d s and Cytherellids. A smaller number is found in the
Polycopids and in Darwinulidae. Xo trace of a procoxale has yet been observed in any
recent forms; it is, however, not quite impossible that such a joint existed originally. Nor
does there seem to be anything of importance to add with regard to this author’s
assumption about the endites on this limb. A powerful endite is found on the coxale in
almost all groups. Without drawing any conclusions from this, I wish, however, to point
out here that an endite or indications of such a process on the basale is found not only in
Halocyprids and Polycopids but also in Asteropids and Philomedes as
well, and in the Cypridinids, where traces of such an endite can also be observed,
these traces are most strong in forms which are presumably to be considered as primitive
(Crossophorus) ; cf. the remark on the group Gypridiniformes below. On the other hånd there
seem to be no reasons that support the assumption that the palp in the Cypridinids
is of a more primitive type than in other forms because of its size. The group Polycopidae,
which is presumably in several respects rather primitive, is characterized by a very short mandible.
Might not this faet be considered to support an assumption that the elongated mandible palp
in Cypridinids and Halocyprids represents a secondary type? The assumption
of a short mandible or at any rate of a moderately long mandible as being the original one in
the Ostracods seems to me to be supported by the faet that in a number of forms in this
group the mandible has been developed as the most important crawling limb on the anterior
part of the body, wliile in others the endopodite of the second antenna has been developed for
this funetion. It seems to me that the easiest way to explain this phenomenon is by assuming
that in the Protostracods both the mandible and the endopodite of the second
antenna were relatively short. With regard to the exopodite of this limb G. M . MÜLLER makes
no assumption, as has been pointed out before. In the recent Ostracods this branch is
always very small; in a number of forms it is peg-like, unjointed and almost bristleless; in
others it is quite absent. It seems to me fairly probable that this branch was comparatively
small in the Protostracods; on the other hånd it seems to be more difficult to say
anything certain about its type. As to whether the protopodite had an epipodial appendage
is very difficult to decide; it may be best to leave this question open.
After having discussed the problem of the mandible of the Protostracods
G. W. Müller put forward the question as to why the endopodite of the second antenna had
been developed into a powerful crawling leg in C y p r i d s, Darwinulids, Nesideids,
Cytherids and Cytherellids; would it not have been more probable, he asks, for
this funetion to have been taken over by the mandibular palp in these groups as in the C y p r
i-d i n i d s? In answer to this question this author writes as follows, p. 194: „So auffallend ähnlich
die Yerwerthung des Mandibulartasters bei den C ypridini d e n und der 2. Antenne bei
den Podocopa (natürlich abgesehen vom Schwimmen bei letzteren) ist, so existirt doch ein
wesentlicher Unterschied: bei den einen haben wir es mit einem Grabfuß, bei den anderen mit
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