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



No organs of fructification have been observed in this species, 

 though it is known from many stations. 



90. OE. CYMATOSPORUM Wittrock & Nordstedt ex Him, 

 1900, p. 80, PI. II, fig. 13. Monoecious; oogonia single, 

 rarely two, subdepressed-globose, pore median or slightly 

 higher ; oospore depressed globose, filling or not quite filling 

 the oogonium, with triple membrane, median pitted, others 

 smooth; antheridia i-4-celled, subepigynous, subhypogynous, 

 hypogynous or scattered ; spermatozoid single. 



veg. cell, 8-10 M diatn., 4-7 diani. long, 



oog., (24- ) 30-40 M " 27-40 M long. 



008., (22-) 27-35 M " (I9-) 22-33 Ji " 



anth. cell, 7-10 M " 9-11 M " 



With other species, Waverley, Mass., A. B. Seymour. Europe. 

 Nearly allied to Oe. Magnusii, but monoecious, with longer 

 cells, larger and more flattened oogonium and larger oospore. 



91. OE. AMEKICANUM Transeau, 1917, p. 231. Dioecious, 

 macrandrous, oogonia single, globose to depressed globose, 

 pore superior ; oospore globose, ellipsoid-or depressed-globose, 

 partly or wholly filling the oogonium ; membrane triple, the 

 median scrobiculate ; antheridia 1-5 celled, frequently alternat- 

 ing with vegetative cells ; spermatozoids binate, division hori- 

 zontal ; basal cell elongate, terminal cell obtuse. 



Charleston, 111. ; New Buffalo, Mich., Transeau. 

 Nearest to Of. foveolatum among our species, but dioecious 

 and of larger dimensions throughout ; the markings are on the 

 median, not the outer wall. 



92. OE. LABVE Wittrock ex Him, 1900, p. 75 ; Transeau, 

 1917, p. 231. Monoecious, oogonia single, depressed-globose, 

 pore median ; oospore depressed-globose, filling the oogonium ; 

 antheridia i-2-celled, subepigynous; spermatozoid single, 

 veg. cell, 10-12 M diatn., 2-6 diam. long, 



oog., 32-38 M " 28-30 M long. 



oo., 30-35 M " 23-26 M " 



anth. cell, 9-10 M " 9-13 M " 



Saugetuck, Mich., Transeau. Frana . 



