101 
Ehrenb., which species was afterwards placed by 
E-alfs under Sphœrozosma^ but C. kept it in sect. I 
Diplartrum of Odontella. Diplarthrum is then as a 
section-name (with description) older than the genus- 
names Isthmosira Kütz. 1845 and Onyclionema Wal- 
lich 1860, in which Odontella filiformis has been 
placed. 
Binatella Bréb. 1835 was regarded by Ehren¬ 
berg 1838 as a genus all too heterogeneous (1 
spec. -- Xanth.; 2 = crystals)^ and Brébisson him¬ 
self in 1842 admitted that most of the species be¬ 
longed to Staur, and others to Cosm. 
Pentasterias Ehrenb. 1836 is only a pentago¬ 
nal Staur. 
Oalodesmium "Wimmer 1836 was so vaguely 
described, that nobody endeavoured a guess before 
Kirchner’ s supposition in 1878 of its being Micra- 
sterias. In Ind. Desm. I considered it included Micr.^ 
Eu. and Cosm. 
Aptogonum was established by Ehrenberg in 
Inf. 1838, p. 381 as ”Nov. Gen.?” upon Desmidium 
aptogonum Bréb., and 1. c. p. 382 E. says: ”Die 
Gattung Aptogonum würde sich bei Odontella anreihen 
als ein Desmidium mit Zapfen an den Enden ohne 
Mittelcanal.” — As Agardh 1832 had given the 
name Odontella to a genus of Diatoms, which name 
is yet in use and valid, Balfs 1848 did not approve 
of Ehrenberg putting several Desmids in that genus, 
but placed Odontella Desmidium as a variety of Apto¬ 
gonum Desmidium. 
For establishement of his genus Arthrodesmùs 
Ehrenberg had 1838 put together 2 species, often 
placed there, often in Xanth.^ 2 species, belonging 
to Scenedesmus^ and one very obscure species, which 
nobody thereafter has seen. That the author himself 
had another idea of his genus than we have usually 
nowadays, is to be seen by his remark in Inf. p. 
