SPIROGYRA 145 



133. Reproducing by aplanospores 198. S. narcissiana 



133. Reproducing by zygospores 199. S. undulisepta 



DIVISION WALL REPLICATE 



134. A circular infold on the end walls of most cells 135 



135. Tubes formed by both gametangia 136 



135. Tubes apparently formed by the male gametangia 159 



136. With I chromatophore in each cell, rarely 2 in some cells 137 



136. With usually more than i chromatophore in each cell. 167 



REPLICATE END WALLS 

 USUALLY ONE CHROMATOPHORE 



137. Fertile cells cylindric or enlarged 138 



137. Fertile cells fusiform-inflated 148 



137. Fertile cells cylindrically ("quadrately") inflated 158 



138. Zygospores ellipsoid 139 



138. Zygospores ovoid 143 



139. Median spore wall smooth, and outer wall smooth 140 



139. Median spore wall smooth, but inner 



layer of outer wall scrobiculate 236. S. venusta 



139. Median spore wall reticulate 222. S. dentireticulata 



140. Diameter vegetative cells less than 24 i^, 141 



140. Diameter vegetative cells between 24 /x and 40 /^ 142 



140. Diameter vegetative cells more 



than 40 /A 233. S. tjibodensis 



141. Zygospores 22-26 (-32) ;u, x 51-103 /a.. 228. S.arta 

 141. Zygospores 30-36 /a x 55-1 10 /a, some 



fertile cells inflated 226. S. spreeiana 



141. Zygospores 25-35^1 x 48-86 ju, sterile 



cells inflated 229. S. tumida 



142. Zygospores 32-42/1 x 80-122 /a, 



outer wall thick, lamellate 231. 5". lamellosa 



142. Zygospores 30-33/1 x 60-82/1, 



outer wall thin 232, S. laxa 



142. Zygospores 35-46/1 x 61-106/1, 



usually ovoid 208. S. semiornata 



143. Median spore wall smooth, outer also smooth 144 



143. Median spore wall smooth, outer wall of 2 layers, of which 



the inner is transparent, scrobiculate 145 



143. Median spore wall granulate, outer 



wall of 2 thin layers 224. S. micro granulata 



