528 



NEW AND RARK FRESHWATER ALG.E, 



iii., f. 14, 15). Known liitherto only from Norwegian and English 

 lakes. 



Genus D a c t y l o t h e c e Lagerh. 

 Dactylothece arcuatum, n.sp. (PI. Ivii., f.:3, 4). 



Cellulfe sparsie in muco amorpho involutse; fronte visie lineari- 

 ellipticie, quam levissime arcuatje, apicibus obtusis; a latere rectai, 

 lineari-ellipticae, lateribus quam levissime convexis, apicibus ob- 

 tusis; membrana tenui; chloroplastide tenuissima, parietali, minute 

 granulosa, interdum in medio di^•isa: pyrenoidibus nullis. 



Cell. long. 14 15, lat. 3-4/x. Lismore (302). 



About 30 cells in a clump, irregularly disposed, enveloped in 

 mucus. Cells linear-elliptic, straight in side-view but from the 

 front arcuate, one side slightly concave, almost tiat, the othei* 

 distinctly convex, ends obtuse. "Membrane thin ; chloroplast 

 delicate, parietal, pale green, minutely granular, sometimes 

 divided in the middle, no pyrenoids. 



Fam. PROTOCOCCACE^. 

 Genus C h a r a c i u m A.Br. 

 Characium guttula, n.sp. (Text-fig. 6rt). 

 Cellulsp corpore ovato levissime curvato, supra rotundato, subter 



Text-fig. 6. 



(a) Characi am </Hf til/a, n.sp.; {h, c) Oh. cer'assiforme var. minimum, ii.var. : 



id) Ch. ornithocephalum A.Br.; (all x 1000). 



rostrato in petiolum longum tenuissimum protracto; membrana 

 tenui; chloroplastide interdum pyrenoidibus singulis continente. 



Cell. long. max. 25-40: corp. long. 12-16, lat. 6-8//. 



Lismore (284, 286). 



