KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 25. N:0 5. 9 



Genera Species 



Vaucheriew 1 1 



Volvocece 3 3 



Palmellacece .. _ 8 1 1 



Protococcacece.. 2 7 



» ? _ 1 1 



Pediastrew ... 6 22 



Ulothrichece - 1 2 



Confervacece .. 3 4 



Chcetophorece.. 1 1 



Oedogoniece. ... 1 3 



Coleochcetece.. „ 1 3 



59 600 

 To the Desnoidieae add the species (not included) of Roy, 



Joshua and Lagerheim ut ante — 120 



Ghlorophyllophycese 59 720 



Algse 74 742 



The Desmidieae of India (including British Burmah) now araount to the large nutnber 

 of 656 species. 



In this list the total is loucb reduced by the coarser Algae baving been partly dis- 

 carded in collecting, and partly afterwards separated, niaiiy forras having thus disappeared: 

 in the above summary forras and varieties are not included in the enumeration. 



With respect to the classification I have adopted in the Desinidieaj, I ha ve en- 

 deavoured to make the sequence of the genera, as to förra, as natural as possible; bu1 

 whatever is done in this direction can only be artificial, as Nature recognizes neither 

 'genera nor 'species. Various scheines have been propounded, sonie of whicb absolutely 

 darken and obscure the very subjeet upon which they are intended to throw light! While 

 pursuing this subjeet I have \\ ritten ont, for comparisons sake, 22 schemes of classification, 

 from those of Mexeoiiim (1840) and Kutzing (1845), up to Cooke (1887); the only one 

 which I can adraire is that long ago proposed by Dr. Wettrock (Points-förteckning öfver 

 Skandinaviens växter. 4. Characeer, Alger och Lafvar. Upsala & Lund 1879 — 80), giving 

 21 genera, in following order: Desmidmm, Hyalotheca, Bambusina, Spondylosium, Sphcero- 

 zosma, Micrasterias, Euastrum, Staurastrum, Xanthidium, Årthr odesmus, Cosmarium, Pleuro- 

 tceniiun, Docidiwu, Tetmemorus, Closterium, Gonatozygon, SpirotcBnia, Penium, Mesotcenium 

 Cylindrocystis and Ancylonema. In this the objectionable division into 'filamentous' and 

 non filamentous 5 forras tinds no place (cfr Abchee in Dubl. Club Proc. Q. J. M. S. p. 192, 

 1866); and moreover the sequence from and to the other classes and families is easy and 

 natui*al, not abrupt. Cooees division of the Desraidieae into the sections Leiosporce and 

 Cosmosporce is certainly incorrect; cfr Lundell Desra. Suec. pp. 2 — 4. As I have found 

 that classifications in which the arrangement of chlorophyll is made a prominent featnre 

 interfere with generic distinctions in some eases, and thus raise awkward objections, sneh 

 as those of Archer, ut supra, p. 71, I have myself been for years past inclined to classify 



K. Sv. Vet. Akud. Hanrll. Band 25. N:o 5 



