SPECIES OF DESMIDS. 93 



mm. Sinus acute inwardly thithophorum, 80 



mm. " rounded and widened inwardly phaseolus, 81 



;;/;;/. " rounded, but not widened inwardly, pseudogranatum^ 158 



nn. Margins crenate or dentate (oo). 



nn. Margins smooth; centre with one verruca; semi-cell elliptical: 



diameter T1) Vo m - ( T 3/^) bireme, 82. 



oo. Ends truncate; diameter T | 7 in. (33^) or larger (pp). 

 co. " " diameter -j-J-0- in. (28jw) or smaller (rr). 



oo. Ends rounded, dentate Lagoeme, * 



//. About i|- times longer than wide; diameter -^-J^ to -g-J-^ in. (33-50/1) 



triplication iy,speciosum, 87 

 //. About -J- longer than wide; diameter ^j-^ to -g-J^ in. (65-70^), 



supraspeciosum, 88 

 //. About -J- longer than wide; diameter yj-^- in. (soyu), 



pychnochvndrum, 89 



rr. Diameter -g-^ to y-gy^ (20-26;^); ends 4 crenate, sides 4-6 crenate, 



subcrenatum, 84. 

 ^'- " TTOTT to TYTO- ( 20 ~ 2 5A'); sides nearly straight, 



Kjdlmanii) 87 



r; - t TjVn- to TWIT (14-25^); granules not radiate; end 4 crenate, 



Blyttii, 87 



jj. Marginal teeth numerous, long, pointed or aculeate, Eloiseanum, 85 



ss. 17, emarginate-truncate quadrifarium, 87 



w. Margins crenate (//). 



//. Basal inflation granulate in vertical lines (////). 

 //. " " with scattered granules . . .pseudopectinoides, 89 



//. " " without granules, the marginal in 8 radiating lines, 



nasutum, 89 



uu. Sinus widening outwardly; granules geminate in rows, 



pectinoides, 88 

 //// " not widening outwardly; cell oblong, diameter -^-^ (33), 



pulchcrrimum^ 90 



uu. " *' " cell orbicular, diameter -^ (50^), 



radiosum^ 90 

 w. End truncate (w). 

 w. End not truncate (zz). 

 ww. Diameter -^ in. (50^) or larger (.v.v). 

 isrw. Diameter smaller than (507,*), -g-J-^ in. (JT). 

 *Journ. R. Micr. Soc., Dec., 1885. 



