148 ZYGNEMATACEAE 



169. Zygospores ellipsoid 170 



169. Zygospores ovoid 171 



170. Chromatophores 2, diameter veg- 

 etative cells 29-32 /x 275. S. marchica 



170. Chromatophores 2-4, diameter 



vegetative cells 28-33/1 244. S. gratiana 



170. Chromatophores 2-3, diameter 



vegetative cells 37-40 /a 245. S. proavita 



170. Chromatophores 2-3, diameter 



vegetative cells 42-58 /a 246. S. transeaiiiana 



171. Zygospores ovoid, diameter 29-32 /x, 



2 chromatophores 275. S. marchica 



171. Zygospores ovoid, diameter 26-29/1, 



2 chromatophores 241. S. tolosana 



171. Zygospores ovoid, about 40 /a x 82- 



86 /A, 2-3 chromatophores 245. S. proavita 



171. Zygospores ovoid, diameter 45-50 /^ 



2 chromatophores 243. S. hartigii 



172. Zygospores ovoid 173 



172. Zygospores ellipsoid 174 



173. Chromatophores 2 to 4, receptive gam- 



etangia cylindrically inflated 247. S. rectangularis 



17^. Chromatophores i or 2, second outer 



spore wall scrobiculate 240. S. areolata 



174. Diameter vegetative cells less than 34 /a 175 



174. Diameter vegetative cells more than 34/1 176 



175. Chromatophores (i-)2, diameter zy- 

 gospores 42-52^1, median wall dotted. 212. S.incrassata 



175. Chromatophores 2, diameter zygo- 

 spores 39-48^1, median wall smooth. . 242. S.hassallii 



175. Chromatophores 2 or 3, diameter zy- 

 gospores 60-64 /^ 25'^- ^- 'i'^^^S^ 



176. Chromatophores 3, diameter zy- 

 gospores 40-48 /i 248. iS". insignis 



176. Chromatophores 3 or 5, diameter 



zygospores 45-60 /u, 249. S. fallax 



REPLICATE END WALLS 

 TWO OR MORE CHROMATOPHORES, MEDIAN SPORE WALL NOT SMOOTH 



177. Zygospores usually ellipsoid 178 



177. Zygospores usually ovoid 181 



