208. Cells shaped otherwise _ 209 



209. Cells oblong or subcylindric, wall sculptured by depressions in 

 transverse series.. Chlorallanthus 



209. Cells shaped otherwise .210 



210. Cells ovate, sometimes broadly fusiform Trachychloron 



210. Cells triangular or tetragonal 211 



211. Cells pyramidal or tetragonal _ Tetragoniella 



211. Cells triangular in face view, flattened and appearing fusiform 



when seen from the side Goniochloris 



212. Cells sessile, without an attaching stipe .213 



212. Cells on a long or short stipe 215 



213. Cell membrane in 2 sections, the upper lifting away for libera- 

 tion of aplanospores Chlorothecium (in part) 



213. Cell membrane in 1 piece 214 



214. Cells globose or subglobose; cytoplasm reticulate, highly vacuo- 

 late; epiphytic on aquatic mosses Perone 



214. Cells shaped otherwise, mostly spindle-shaped, without reticu- 

 late cytoplasm; epiphytic or epizoic Characiopsis (in part) 



215. Cells with a vase-shaped, pitcher-shaped, or globular lorica 



which has an anterior neck and opening Stipitococcus 



215. Cells without such a lorica _... 216 



216. Cells elongate-cyhndric, straight or cvuved, with parallel 



margins Ophiocytium ( in part ) 



216. Cells shaped otherwise 217 



217. Cells mostly club-shaped or pear-shaped; wall composed of 2 sec- 

 tions, the upper part lifting away for escape 



of aplanospores Chlorothecium ( in part) 



217. Cell wall composed of 1 piece; cells spherical, fusiform, or ovoid — 218 



218. Stipe a slender thread, much longer than the 



cell body Peromelia ( in part ) 



218. Stipe shorter than or about equal to the cell body 



in length Characiopsis ( in part) 



219. Plants attached by a stipe - 220 



219. Plants not attached by a stipe - .....221 



220. Protoplast in a globular lorica with an anterior opening; cells in 



short linear series on one stalk ___ Peroniella (in part) 



220. Protoplast not contained in a lorica; cells elongate-cylindric; 



cells in corymbose colonies Ophiocytium (in part) 



221. Cells inclosed by a mucilaginous sheath 222 



221. Cells not inclosed by mucilage — 224 



222. Cells 2-16 within a globular, gelatinous envelope —Chlorobotrys (in part) 



222. Cells arranged otherwise -- —223 



223. Cells numerous within an irregularly-shaped gelatinous 



matrix Gloeohotnjs 



223. Cells solitary or in pairs at the end of falsely branched 

 gelatinous tubes .._ Mischococcus (in part) 



224. Cells in multiples of 2 or 4, forming loose cushions, or gregarious 



on submerged plants ._ — - Chlorellidiopsis 



224. Cells arranged otherwise 225 



225. Cells with walls of 2 pieces which separate and persist after liber- 

 ation of autospores; cells only incidentally clustered ..Diac^ro* (in part) 



225. Cells with wall of 1 piece; wall breaking dovra irregularly to 



liberate autospores; cells incidentally clustered Botrydiopsis (in part) 



[588] 



