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chapter.
Cypridi m da
Hatocyprida
Cythenda
Cypridae.
S e e m s a n y t hing b u t p r o b a b le t h a t C. CLAUS’ v i e w t h a t t h e C y p rids
li a v e develo p ed f r o m m a r i n e C y t h e r i d s is c o r r e c t. But it is quite
impossible to solve this problem defiuitely in the present state of affairs.
It seems to me by no means impossible t h a t Cypriformes have
branche d off from the a n c e s t o r s of the Halocyprids after the
latter had been differentiated
from Cypridinids and P o 1 y c o p i d s.
This question will only be able to be
solved after the solution of the problem as to
whether the foliaceous type of the fifth and sixth
limbs of Cypridinids is a primary or a
secondary one. A number of features in the
anatomy of the Polycopids s e e m to
indicate that this gro up branched
off from the other groups at a very
early stage, presumably before the
Cypridinids, and consequently long
before the time indic ated in the
pedigree drawn up by G. W. Müller. On the other hand it seems to
me quite impossible at present to decide when the original forms
of the Cytherellids were differentiated from other Ostracods.
It will be seen that the result of this en quiry has been to a great
ex tent negative. Only in a comparati vely few respects has it seemed to me possible
to follow more or less without reservations the views of previous writers as to the Organization
of the Protostracods and the natural grouping of the recent Ostracods; in
most cases I have been compelled to doubt or even to reject the suggestions made by them.
1 did not think I could construet any „genealogical tree“, nor did it seem possible to accept
any of those previously drawn up. I have only been able to bring a small number of new facts
into the discussion. This is due especially to the faet that only a few phylogenetically important
forms have been included in the literature of late. Only one such form has, as far as I know,
been added; I refer to the curious genus Thaumatocypris. But I hope that this investigation
will not prove to be of no importance.
Fig. X. — The pedigree ot the recent Ostracods
according to C. Claus’ statements.
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