Fresh-water Mgee, &c. By A. W. Bennett 15 



Pinniilaria major W. Sm. 



„ viridis W. Sm. 



„ oblonga W. Sm. 



„ radiosa W. Sm. 



„ gracilis Ehrb. 



Stauroneis Phoenicentron Ehrb. 



„ gracilis Ehrb. 

 Synedra radians W. Sm. 

 „ Ulna Ehrb. 

 ,, fasciculata Ktz. 



* ,, capitata Ehrb. 

 Gomphonema constrictum Ehrb. 



„ acuminatum Ehrb. 



Himantidium pectinale Ktz. 

 *Odontidium mutabile W. Sm. 

 Fragilaria capucina Desm. 

 Diatoma vulgare Bory. 

 „ elongatum Ag. 

 Tabellaria flocculosa Ktz. 



Desmidie^. 

 Hyalotheca dissiliens Sm. Comparatively very scarce. 



* „ mucosa Ehrb. 

 Didymoprium Borreri Ralfs. 



* „ Grevillei Ktz. Bog pools, Mawgan. 

 Sphgerozosma vertebratum Breb. 



Docidium nodulosum Breb. 

 „ truncatum Breb. 

 „ clavatum Ktz. Yery common in bog pools. 



* „ Ehrenbergii Ealfs. Bog pools, Mawgan. 

 „ baculum Breb. 



*DocrDiuM GEANULATUM n. sp. Fig. 17. 



Frond minute, about five times as long as broad, 50 /* by 10 jx, 

 slightly constricted in the middle, conspicuously covered with pearly 

 granules. Endochrome dark green, with a lighter transverse band in 

 the centre. 



Bog pool, Mawgan, occasional. About the size of D. minutum 

 Ealfs. Nearest to D. asperum Ealfs, from which it differs in its 

 dimensions, in the central constriction, and in the ends not being dilated. 



Cylindrocystis diplospora Lund. Frequent in bog pools. 

 Penium margaritaceum Ehrb. 

 „ cylindrus Ehrb. 

 „ digitus Ehrb. Much the most common desmid, and 



remarkably variable in size. 

 „ interruptum Breb. 

 „ Brebissonii Ealfs. 

 Tetmemorus Brebissonii Menegh. 

 „ granulatus Breb. 



„ penioides Benn. (Journ. E. Micr. Soc, 1886, p. 13, 



t. ii. f. 26), Bog pool, Mawgan. 



