62 SPECIES OF ALG.E. 



75. MESOCARPUS. 



Diameter of filament 50/1; spore smooth ..... crassa, 230 



" " " 1 8/4 or less (a). 



" " " 20/4 to 32/4 (c). 



a. Spore membrane punctate; filaments 9-15/4 diam. nummuloides, 231 



a. " " smooth (b). 



b. Filaments 8-10/4 in diameter ........ parvulus, 230 



b. " 10-18/1 " " ........ recurvus, 231 



r. Spore membrane punctate; filaments 25-32/4 in diam. robustus, 231 

 e. " " smooth (</). 



^/. With short branchlets from the middle of a cell . radicans, 231 



d. Without branchlets (e). 



e. Diameter of spores and filaments about equal . . scalaris, 230 

 e. " " " twice that of the filaments . macrospora, 230 



76. PLEUROCARPUS. 



Diameter of filaments 25-30/4 ........ mirabilis, 232 



" " " 37-40/4 ....... Columbianus, 232 



77. PLAGIOSPERMUM. 



One species ................ tenue, 233 



78. GONATONEMA. 



One species .............. ventricosum, 233 



79. STAUROSPERMUM. 



Diameter of filaments 14-20/4, becoming bluish, spore smooth, 



capucinum, 234 



8-1 2/^; spore punctate . . quadratum, 234 



" " " 6-8/4; spore smooth .... viridc, 234 



80. CRATEROSPERMUM. 



One species ............... Icetiverens^ 235 



8l. CALOTHRIX. 



g Diameter including sheath 6-8/4 at base .... gracilis, 237 

 " " " 10-14/1 (a). 



a. Sheath lamellose, ends colorless, torn into fibres; cells 6-8 f.i in diam. 



Meneghiniana, 238 



a. " not fibrous at ends; brown or black in mass, gypsophila, 237 

 a. " " " " " bluish, rarely brownish, Dillwynii, 237 



