99 
-i: Ursinella Turpin 1820—28 was so badly de¬ 
scribed and sketchedj that nobody before Kuntze 
could approve it as a genus, although some figures 
have been supposed to belong to Cosmarium. 
The description of Micrasterias Ag. 1827 was 
really so bad and so incomplete, that much doubt 
arose as to the intention of the author. Ehrenberg, 
and Kützing partly, had in view a very different 
genus, Pediastrum of Meyen 1829. This interpreta¬ 
tion did not meet with success, after Meneghini 
1840 had given a more complete description and 
Al. Braun (Alg. unie. 1855 p. 64 et 107) had 
shown, that specimens of ’’’’Micr. fiircata'^ in the Herb. 
Ag. belonged to Micrasterias rotata Ralfs. Probably 
0. Kuntze thought there was not sufficient evidence 
with regard to these 2 genera, termed Micrasterias^ 
and not approving of Agardh’s genus, he deemed 
Mier. falcata Corda 1835 as the type of a new ge¬ 
nus Micrasterias^ identical with Ankistrodesmus Corda 
1838, although Corda himself did not quote Micr. 
falcata under his new genus, only saying: ”J’en con¬ 
nais deux espèces — — fusiformis — — convolutus. 
(Cfr Hedwigia 1893 p. 147—9.) 
Tessarthonia Turp. 1828 without any diag¬ 
nosis of the genus with the species moniliforme has 
been disputed ; some authors have regarded it iden¬ 
tical with Cosm. moniliforme Ralfs, others have sup¬ 
posed Turpin’s figures not to belong to the Desmids. 
Kuntze 1891 said: genus delendum. Ehrenberg cor¬ 
rected the name into Tessarathra and Tessararthra. 
Staurastrum Meyen 1829 with regard to one 
species has been approved, but to a different extent 
by different authors. 
Euastrum Ehrenb. 1832 and Xanthidium 
Ehrenb. 1834 had already at the beginning a va¬ 
rying extent ; JEu. included Cosmarium and Micraste- 
riaSj Xanth. contained several Staurastra. 
