PLATE LVI. 
| 50 MICRONS 


Tierany 
Figs. 532 and 533. Oedogonium crenulatum Wittr. (After Wittrock)......... 171 
Fig. 534. Oe. crenulatum v. gracilius (Nord.) Hirn. (Redrawn from Hirn)...171 
Pig; doo. Oe. plicatulam Wittr: ~(Redrawinirom Hirn)............:.2c.ouee.- 170 
Figs. 536-538. Oe. lagerstedtii Wittr. (Redrawn from Hirn)................. 170 
Bite dsoe COE, OFlIauOICUI.W ihuies Elites sons ss cca teeet 142 
Fig. 540. Oe. oelandicum f. minus Borge. (Redrawn from Borge)............ 142 
Fig. 541. Oe. pulchrum Nord. and Hirn. (Redrawn from Hirn)..............170 
Bies42 Oe. boreale Hur. s(kedrawn trom Elirm):...)...-...c.-ee+es0en oO) 147 
erate IO oes TEV PATIL AANO Wi le ese oaths = ss, .seie 2c no, ote wares oom oe Boge 142 
Hig.044. Oc: platygynim Wittr. “(After Wittrock). .°. 5... .5.00.... 0... t ae, 143 
Fig. 545. Oe. platygynum f. obtusum Hirn. (Redrawn from Hirn)............ 143 
Fig. 546. Oe. platygynum v. continuum Nordst. (After Nordstedt)...........148 
Fig. 547. Oe. platygynum v. novae zelandiae Hirn. (After Nordstedt)........ 144 
Een ore CONE ACMIM MISE AUN elles, fos Veale sas eles satan ie 146 
(Figs. 533, 537, 541, 544 show also oogonia in optical section seen from above.) 
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