Palaeontology. — “The identity of the genera Poloniella and 
Kloedenella” By Miss J. E. van Veen. (Communicated by 
Prof. J.W. Mout.) 
(Communicated at the meeting of December 18, 1920). 
In the year 1896 a treatise appeared by Prof. Dr. Géricu about the 
Palaeozoicum of the Polish middle mountain range. In this treatise 
the author instituted the new genus Poloniella (4, p. 388) for a few 
carapaces and valves of formerly unknown Ostracoda, originating 
from the middle devonian Ostracoda marl of Dombrowa near Kielce. 
These remains he united into one species viz. Poloniella devonica. 
Some twelve years afterwards the two American palaeonotologists 
Dr. UrricH and Dr. Basser supplied a contribution to the know- 
ledge of the Beyrichiidae. On this occasion the new genus Kloede- 
nella (8, p. 317) was founded also, under which group they intended 
to bring together eight species at the least. 
In 1914 Prof. Dr. Bonnema (2, p. 1087; 3, p. 1105) was able to 
amplify the characteristics of the genus Kloedenella as given by 
Unricn and Bassier as a resuit of his investigation into the nature 
of the Ostracod, which Dr. Aurrt Krauser formerly described under 
the name Beyrichia hieroglyphica. 
In comparing what the above mentioned authors have said about 
the genera Poloniella and Kloedenella, it is obvious that the latter 
are identical. It should however be observed that what BoNNEMA 
takes to be the anterior part of the carapace — and rightly in my 
opinion — is considered the posterior part by the others. As a 
natural result the valve, which is the left one, according to BONNEMA, 
is called the right one by the others. 
Thus Bonnema found as the most characteristic feature of the genus 
Kloedenella that the right valve before the straight part of the hinge 
line has a notch in which a process of the left valve fits. (fig. 3). 
In the genus Poloniella a similar connection of the valves seems to 
be present. GiricH does not mention this fact emphatically, but as he 
writes: “Ganz am vorderen Ende jedoch tritt der linke Saum wieder 
zurück und auf der hinteren Kantenhälfte springt der rechte Saum 
sogar stark über”, | should conelude from this that it occurs here also. 
Besides BONNEMA had found that in the genus Kloedenella the 
right valve overlaps the left one at the hinge line, whereas the 
Opposite is the case with the free edges. In accordance herewith, 
GüricH writes ‘“.... greift am Schlossrande die linke Klappe in 
einer gradlinigen Leiste vorspringend iiber den entsprechenden Rand 
