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The special
classification of this
group is very
un-satisfactory.
Uncertainty
and incompleteness
oj thc descriptions
oj species.
so — points mom inwardly, their outer charactere present only a few certain and phylogenetically
important fixed points, while, on the other hand, a careiul investigation of the inner structure
in these groups is often likely to give good and important results.
What I refer to is the special classification............
Even at a rather early date H VECKEL put forward the supposition that the marine
Ostracods might prove tq be exceedinglv rich in species. This supposition has been fully
confirmed by the following investigations. Thus G. W. MÜLLER in his synoptic work on the
Ostracods in ,,Das Tierreich“, 1912, includes no less than 1719 living Ostracod species
and of these the marine forms compose the vast majority. To judge from the most recently
published works and from the expérience I had myself in working out this treatise, the number
is, in addition, far from exhausted.
Under these circu instances it would be a great pity if the quality of the descriptions of
the species were not to correspond to their quantity.
Even in Fr. Dahl’s work on the C y t h e r i d s of the Baltic, 1888, we find on p. 1 the
following statements, unfortunately only too true, which throw light on this state of afEairs:
„Ich mußte aber bald einsehen, daß sich schon dem Vorstudium zu einer solchen Arbeit,
d. h. der Bestimmung der Arten, ganz erhebliche Schwierigkeiten entgegenstellten. Selbst
nach eingehender Prüfung konnte ich nicht mit Sicherheit angeben, ob meine Bestimmung
wirklich richtig sei. Es lag dies theils daran, daß in der vorhandenen Literatur gar keine .oder
ungenügende Zeichnungen vorliegen, und doch dürften gerade in dieser Thiergruppe genaue
Zeichnungen unbedingt nothwendig sein . . . .“
G. W. MÜLLER States that, out of the 1719 Ostracod species included in his work
of 1912, only 921 are to be considered as „sichere“, the remaining 798 are „unsichere Species“.
Mv own experience goes to show that even a rather considerably greater percentage of these
species are to be denoted as uncertain.
On a doser study of the numerous diagnoses of marine species of this group that are
found in the literature one cannot but be struck almost continually by two facts: first the
indefinite and uncertain nature of ail that is written and secondly the fewness of the charactere
that are taken into considération.
Most of these species are, as a matter of fact, so superficially described and reproduced
— the diagnosis consista only of a general description of the habitus — that certain identification
is quite impossible merely because of this.
Tliis superfieiality has had the result that obvious errors have very often crept in.
Only a few authors, such as G. \Y. MÜLLER and N. HIRSCHMANN’, seem to have troubled about
any great exactitude with regard to details. But not even they can escape criticism for lack
of care, a faet that I had an opportunity to observe, for instance, in the case of G. W. MÜLLER,
in a number of verificatory investigations. As the conditions now are, it is at least equally
probable, in the cases where a difference is found between the form investigated and
the description or figure of a species formerly treated in the literature, that this
deviation is due to lack of precision in the description or the figure as that the difference
actually exists.
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