107 
but these words allude probably to a Fleur otæniox>sis, 
Italfs quoted Fit. angulosus under Cosm. cucumis^ 
but its size (long.: 90—125 lat.: 45 jut) argues 
rather in favour of Cosm. {Fleur otœniopsis) Deharyi. 
Stauroceras Kütz. 1845 has been regarded by 
most authors as a subgenus or section of Closterium. 
Trichodictyon Kütz. 1845 is according to 
Archer 1864 identical with Cylindrocystis crassa. 
Entospira Kütz. 1847. Cfr. Falmogloea Kütz. 
1843, above! 
”Die Infusionsfchierchen” by Ehrenberg 1838 is 
the first great work, in which all the known species 
of Desmids are treated and most of them described 
and figured, although the number of admitted species 
does not reach more than 43. Ehrenberg publishes 
here mostly his own observations, but he gives an 
account of other known species, though he perhaps 
too often tries to identify them with his own. Several 
of his genera are not naturally limited, Desmidium 
contains 5 Staurastra^ Xanthidium 2 Staur.; Fentaste- 
rias is a Staur.; Arthr odesmus comprises all the See- 
nedesmi. Odontidium^ a Diatom genus, contains species 
of Desmids and 2 other algæ. In Euastrum are Mi¬ 
er aster ias auct. rec. and Cosmarium put in, while his 
Micrasterias is Fediastrum Meyen. Fen'ium., Netrium 
and Fleurotœnium are included in Closterium. Several 
of his species are collective comprising 2—5 species 
of later authors, as: Xanthidium fascicidatum., Euastrum 
Rota., Eu. ansatum, Eu. margaritiferum, Closterium 
Lunula, Cl. moniliferum, Cl. Dianæ, Cl. Trabecida 
and Cl. Digitus. 
In ^^Synopsis Desmidearum hucusque cognitarum” 
of J. Meneghini 1840 the number of true Desmids 
amounts to 80, especially by new contributions of 
Brébisson. Certainly systematic improvements are 
made, so that almost all the Staurastra are put toge- 
