144 ZYGNEMATACEAE 



124. Median spore wall punctate, di- 

 ameter vegetative cells 27-30 /a. . . 189. S. punctijormis 

 124. Median spore wall coarsely punc- 

 tate, diameter vegetative cells 



18-22/X 183. S. collinsii 



124. Median spore wall coarsely punc- 

 tate, diameter vegetative cells 



13-14/^ 181. 6'. prescottii 



125. With I chromatophore (rarely 2 in some cells) 126 



125. With 2 or ^ chromatophores (rarely i) in each cell 127 



126. Median spore wall smooth, gam- 



etangia strongly reflexed 190. S. reflexa 



126. Median spore wall punctate 191. 5. micropunctata 



126. Median spore wall irregularly 

 reticulate, diameter vegetative 



cells 27-33 /x 187. S. esthonica 



126. Median spore wall scrobiculate . . 188. S.suomiana 

 127. Spores ellipsoid to ovoid, median wall 



punctate 1 14. 5". schmidtii 



127. Spores ovoid, outer median wall cor- 

 rugate, inner finely reticulate 192. 6\ corrugata 



128. Chromatophore i in each cell 129 



128. Chromatophores 2 to 5 in each cell 130 



128. Chromatophores 5 to 10 in each cell 131 



129. Median spore wall smooth, diameter 



vegetative cells 40-45 m n)6. S. visenda 



129. Median spore wall smooth, diameter 



vegetative cells 53-56/A 197. S. Iiungarica 



129. Median spore wall punctate 193. S. rugulosa 



130. Chromatophores 3, median spore 



wall irregularly corrugate 136. S. grossii 



130. Chromatophores 2-4, median 



spore wall areolatc 194. S. wabashensis 



130. Chromatophores 3-5, median 



spore wall reticulate 178. S. texensis 



131. Chromatophores 5, spores ovoid 195. S.conspicua 



131. Chromatophores 7-10, spores lentic- 

 ular lyy. S. hydrodictya 



DIVISION WALLS SEMIREPLICATE 



132. An infold extending halfway around the wall and alter- 

 nating in position in adjoining cells 133 



