62 



SPECIES OF ALGjE. 

 75. MESOCARPUS. 



§ Diameter of filament S°M': spore smooth crassa, 230 



§ " " " i8>t or less((2:). 



§ " " " 2o/< to 32/< {<■). 



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



a. " " smooth (^). 



b. Filaments 8-io/^ in diameter . ... . parvulus, 230 



b. " io-i8yU " " recurvus, 231 



c. Spore membrane punctate; filaments 25-32;^ in diam. robustus, 231 

 e. " " smooth {d). 



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



d. Without branchlets {e). 



e. Diameter of spores and filaments about equal 

 e. " " " twice that of the filaments 



scalaris, 230 

 macrospora, 230 



76. PLEUROCARPUS. 



Diameter of filaments 25-30^1* . ... 

 37-40/^ 



One species 

 One species 



77. PLAGIOSPERMUM. 



78. GONATONEMA. 



. mirabilis, 232 

 Columbtanus, 232 



tenue, 233 

 ventricosum, 233 



79. STAUROSPERMUM. 



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



capucinum, 234 

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



" " " 6-8/<; spore smooth . . . viride, 234 



80. CRATEROSPERMUM. 



One species 



lativerens, 235 

 gracilis, 237 



81. CALOTHRIX. 



§ Diameter including sheath 6-8/i at base 

 § " " " io-i4/< {a). 



§ " " " iS-3°y"('^)- 



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



Meneghiniana, 238 

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

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



