62 TUFTS COLLEGE STUDIES, VOL. IV, No. 7 



81. Oogonium 36-45 M diani., usually seriate. 60. Of. macrandrium. 

 81. Oogonium 29-36 n diatn., single or 2. 85. Oe. propinqnmn. 



82. Division superior; oogonium 14-23 M diam. 95. 



82. Division apical ; oogonium over 30 M diam. 83. 



83. Oogonium 33-56 M diatn. 62. Of. acrosporutn. 



83. Oogonium 66-82 M diam. 86. Of. tentoriale. 



84. Oogonium opening by a pore. 85. 



84. Oogonium opening by a lid. 64. Of. undulatum. 



85. Membrane of oospore smooth. 86. 



85. Membrane of oospore ribbed. 63. Of. cyathigerum. 



86. Oogonium 28 M diam. 87. Of. depressum. 



86. Oogonium 55 60 M diam. 73. Oe. cataract urn. 



87. Oospore globose. 88. 



87. Oospore ellipsoid. 69. Of. pluvialf. 



88. Division of oogonium median. 89. 



88. Division of oogonium inferior. 68. Of. platygynum. 



89. Oospore nearly or quite filling oogonium. 90. 



89. Oospore not nearly filling oogonium 67. Oe. Areschougii. 



90.. Oogonium 20-27 M diam. 65. Oe. Rothii. 



90. Oogonium 30-38 M diam. 91. 



91. Oospore depressed-globose. 66. Oe. decipiens. 



91. Oospore globose. 74. Oe. londinenst. 



92. Dioecious, oogonium 24-27 M diam. 3. Oe. Afagnusii, 



92. Monoecious, oogonium 30-40 M diam. 90. Of. cytnatosporum. 

 93. Monoecious, vegetative cells 14 23 M diam. 13. Oe. foveolatuin. 

 93. Dioecious, vegetative cells, female, 24-48 diam. 



91. Oe. americanutn. 



94. Oogonium 23-28 M diam. i. Oe. cryptoporuttt. 



94. Ooogonium 32-38 M diam. 92. Oe. laeve. 



95- Oogonium ovoid, larger below. 61. Oe. longatum. 



95- Oogonium obovoid, larger above. 93. Oe. rugnlosutn. 



Page 229, after description of OE. RUKESCENS, insert, 



Var. EXIGUUM Him, 1900, p. 76, PI. I, fig. 5. Vegetative 

 cells more slender, oogonium single or 2, oospore subdepressed- 

 globose, antheridium 3-celled. 111., Transeau. Europe. 



veg. cell, 5-9 M diam., 4-10 diam. long. 



oog., 22-24 M " 20-28 Mlonj?. 



00*., 20-22 M " 17-23 M " 



anth. cell, 5 M " 10-12 M " 



Page 233. before OR. PLAGIOSTOMUM var. GRACILIUS, insert, 



OB. PLAGIOSTOMUM Wittrock ex Hirn, 1900, p. 100, PI. VI, 

 fig- 39- 



