Fresh-water Algse, &g. By A. W. Bennett. 7 



Odontidium hiemale Ktz. Ambleside. 

 Fragilaria capucina Desm. 

 Diatoma vulgare Bory. 



„ grande W. Sm. 



,, elongatum Ag. 

 Tabellaria flocculosa Ktz. 

 „ fenestrata Ktz. 

 Melosira varians Ag. 



Desmidie^. 



Hyalotlieca dissiliens Sm. 

 Didymoprium Borreri Ealfs. 

 Desmidium Swartzii Ag. 



„ quadrangulatum Ealfs. 



Frequent in bog pools, Loughrigg, forming, together with 

 Hyalotlieca dissiliens, dense green slimy floating masses. 

 SphaBrozosma vertebratum Breb. 

 „ excavatum Ealfs. 



Micrasterias denticulata Breb. 

 „ rotata Grev. 



MiCEASTERIAS COENUTA n. Sp. Fig. 6. 



Frond oval, very large, 0-355 mm. in length, 0"305 mm. 

 in breadth. The two terminal lobes urn-shaped, very light green, 

 slightly projecting beyond the margin, and quite distinct for their 

 whole length, reaching down to an oval quite colourless piece in 

 the centre ; ends of terminal lobes colourless, concave, not dentate 

 or fimbriate. Each quarter with two deep and three less deep 

 incisions. Margin 27 • 5 /* wide, perfectly colourless, consisting of 

 six distinct pieces, each with a deep indentation. 



Stream between Codale and Stickle Tarns, at an elevation of 

 about 1800 feet. Seems quite distinct, not only from its very 

 large size, but in other characters. Differs from M. denticulata in 

 the prominence and distinctness of the terminal lobes ; from 

 M. rotata in the terminal lobes and segments of the colourless 

 margin not being bidentate. 



Micrasterias fimbriata Ealfs. 

 „ papillifera Breb. 

 „ truncata Corda. 



„ crenata Breb. 



Holocystis oscitans Hass. (Micrasterias oscitans Ealfs ; 

 Tetrachastrum 7nucronatuin and oscitans Dixon ; Micras- 

 terias mucronata auct.). Figs. 7-10. 



This very polymorphic species seems to me to have been well 

 separated by Hassall as the type of a distinct genus ; and, according 



