ZYGNEMA 21 



43, Spores usually globose, diameter pits 



1-2 /A 60. Z. cruciatum 



43. Spores cylindric-ovoid, diameter pits 



i-2ju. 61. Z. cylindrosporum 



44. Diameter pits on median wall 



2-6.5 >^ 92. Z. \wangtungense 



44. Diameter pits on median wall 4-5 A^ 64. Z. inconspicuum 

 44. Diameter pits on median wall 



7-12 ft 58. Z. transeauianum 



45. Receptive gametangia cylindric or slightly enlarged 46 



45. Receptive gametangia much enlarged or inflated 49 



46. Diameter vegetative cells average less than 27 /x 47 



46. Diameter vegetative cells average more than 27 /x 48 



47. Median spore wall with scattered punc- 



tations 90. Z. mucigenum 



47. Median spore wall smooth 68. Z. chalybeospermum 



47. Median spore wall punctate 71. Z. melanosporum 



47. Median spore wall scrobiculate and 



carinate 72. Z. excompressum 



48. Median spore wall smooth 69. Z. cyaneum 



48. Median spore wall densely punc- 

 tate 74. Z. azureum 



48. Median spore wall scrobiculate 79. Z. catenatum 



48. Median spore wall pitted 77- ■^- ornatum 



49. Diameter vegetative cells less than 20 /x 50 



49. Diameter vegetative cells 20-30/^ 51 



49. Diameter vegetative cells more than 30 /x 52 



50. Vegetative cells 14-17 ft in diameter 67. Z.atrocoeruleum 

 50. Vegetative cells 18-24/u, in diameter 70. Z.collinsianum 



51. Median spore wall with pits 1-2 /a in 



diameter 73- '^- peliosporum 



51. Median spore wall with pits 3-4 /^ in 



diameter 15- ^' carinthiacum 



51. Median spore wall with pits 4-5/^ in 



diameter 70. Z. collinsianum 



51. Median spore wall with pits 7-11/^ in 



diameter 76. Z. pawneanum 



52. Pits o£ median wall about 6fi in 



diameter 17- ^- ornatum 



<yi. Pits of median wall about 3 /a in 



diameter 78. Z. excommune 



