1 



NETEIUM. ('>'.) 



Italy. Hungary. Norway. Sweden. Eussia. Lap- 

 land. United States. 



This species is well characterized "by the transverse division 

 of the cliloroplasts, so that four are present in each cell, 

 arranged in a longitudinal series. The conical apices also 

 enable it to be easily distinguished from other species of 

 \rtriiiui and of Penium. The radiating' longitudinal plates of 

 the chloroplasts resemble those of Peiiiiiminoi'e than the other 

 species of Netrium by reason of the entire, free edges, but the 

 structure of the cell-wall places this plant in the Spirotaeniese. 



Var. sectum nob. (PI. VII, fig. 3.) 



Penium interrujitum var. sectum West, Alg. W. Ireland, 1892, p. 127 ; 

 Xurdst. Index Desmid. 1890, p. 148. 



A variety with the apices suddenly truncate ; cell- 

 wall becoming brown in colour. 



Length 258 ^i ; breadth 47 /< ; breadth of apices 

 20-22 |i. 



IRELAND. Near AVestport, Mayo ! 



