100 
Oolpopelta Corda 1834 was published with¬ 
out any description of the genus. The only species, 
viridis^ was afterwards ranked among those Cosmaria^ 
which have been set down as a proper genus, Bys- 
phinctium. But that the establishment of such a genus- 
as the latter was not Cor da ’s intention is clear, be¬ 
cause his new species deplanata 1839 cannot belong 
to Dysphinctium. 
Corda did not in 1834 describe his new genus 
Oosmarium, but only some species, and giving a ge¬ 
neric diagnosis in Aim. d. Carlsb. 1839, he included 
also the genera Euastrum and Eantliidium. 
Pleurosicyos was described by Corda 1834 as 
”octangulaire” and fig. 69 (”animalcule vu d’en haut”) 
is really octagonal with concave sides. That Corda 
had seen living specimens of Penium {Netrium) Digi¬ 
tus sensu lat. is evident from his fig.. 68 and already 
Ehrenberg identified this figure with his Clost. Di¬ 
gitus. But fig. 69 is probably constructed by Corda, 
as any such angular Clost. or Pen. does not exist, 
as far as we know. That the processes between the 
notches on the chloroplastes have been regarded 
by Corda as ”trous pedaux” agrees with the view, 
that he and other authors held, that Desmids were 
animals. I think that the name Pleurosicyos ought 
to be reserved for the plant, which possibly exists 
and is quite identical with Cor da’s figures, or at least 
a little angular. As Netrium now is separated from 
Penium^ the name Pleurosicyos ought to bee trans¬ 
ported from Penium to Netrium by those, who with 
Kuntze like the resurrection of Corda’s generic name. 
Corda did not give any description of his new 
genus Sphærozosma 1834 but only a very short 
explanation of the figures of Sph. elegans. Ehren¬ 
berg united it with Odontella^ but Corda preserved 
his genus in 1840, adding a new species. Corda 
did not then take up in his genus Odontella filiformis 
