131 



Genus Pleurotaenium Naegeli 1849. 



18. Pleurotaenium truncatum (Breb.) Naeg. 



De Brébisson in Cheval. Microscope, Naegeli : Gatt. einz, 

 Algen. 



In a single sample. 



Genus Tetmemorus Ralfs 1844. 



19. Tetmemorus granulatus (Breb.) Ralfs. 



De Brébisson ibid. Ralfs in Ann. Mag. Nat. Hist. 

 From Schwarze Lacke. 



Genus Euastrum Ehrbg 1832. 



20. Euastrum Dìdelta (Turp.) Ralfs. 

 TuRPiN : Apergu organographique, Ralfs ibid. 

 A single specimen in one sample. 



Genus Cosmarìum Corda 1834 



m 



21. Cosmarium Debaryi Arch. 

 Archer in Pritchard Infus.' 

 A few specimens observed. 



Size : Long 107 [a, lat. 52 \s., lat. isthm. 37 [jl. 



22. Cosmarium globosum Bulnh. 

 BuLNHORST in Hedwigia 1861. 

 Scarce in a single collection. 

 Size : Long 30 [x, lat. 22 [i. 



23. Cosmarium Hammeri Reinsch. 

 Reinsch : Spec. Gener. Alg. 

 Common in a couple of samples. 



24. Cosmarium humile var. striatum (Boldt) Schmidle. 

 BoLDT : Sibir. Chlorophylloph., Schmidle : Beitr. Alp. Algen. 

 This widely distributed Desmid was general. 



25. Cosmarium impressuJum Elfv. 

 Elfving : Anteckn. Finska Desm. 

 Quite common. 



26. Cosmarium Majae sp. n. 



Cells minute, a little longer than broad. Semicells pyramidate- 



