14 



NEW AND RARE FRESHWATER ALG^, 



are generally retracted into an oval (53 x 32/x), oblong (53 x 4:2/x) 

 or more rarely globular (diam. 42/x) zygospore. 



Text-fig. 5. 

 Mougeotia Icetevirens (A.Br.) Wittr. ; (a) conjugating filaments with unusu- 

 ally large pyrenoids; {h, c, d, e) types of zygospores; (all x 330). 



CHLOROPHYCE^. 

 Fam. VOLVOCACE^. 

 Genus C a r t e r i a Diesing. 

 Carteria rugulosa, n.sp. (PI. Iv., f.l^ 2). 

 Cellulse reniformes, in fronte acuminatse, a tergo concavse, 

 angulis posterioribus rotundatis. A vertice late ellipticse. Meni- 

 brana paullo rufescens, jugis granulatis convergentibus 12, longi- 

 tudinaliter dispositis, ornata. Cytoplasma retracto gioboso, 

 stigmate juxta apicem. 

 Long. 17, lat. 23, crass, 17/x. Lismore(311, 312). 



A most curious form, noted in some numbers. The cell- wall 

 is much larger than the mass of cytoplasm, and is reniform or 

 rather broadly obcordate in shape, with 12 coarse longitudinal 

 ridges bearing a series of granules. The ridges converge to a 

 point in front and behind. The cell-wall was rufescent, and the 



