CEDOGONIUM. 87 



and were attached to the female plant in the neighborhood 

 of the sporangia. The spines are thorn-like, sharp at the 

 points, but robust at the base." Wood, Fresh- Water Algse 

 of the United States, p. 198. With the exception of the 

 lateral pore above the middle, this plant might be identified 

 as Oe. Aster, Wittr. 



Plate LXXXV, figs. 13, 14. 



b. Oospores ellipsoid. 



OEDOGONIUM: HYSTRIX, Wittr. 



Gynandrosporons or idio-androsporous ; oogonia single, 

 ellipsoid to globose ellipsoid, opening by a pore in the 

 middle 5 oospore same form as oogoiiium, nearly filling it, 

 coated with subulate spines ; androsporangia 2-3 celled ; 

 terminal cell obtuse, dwarf male stipe 2-celled, moderately 

 curved, seated on the supporting cell ; spermogonium one- 

 celled. 



Diameter veg. cells, 17-28 //; 2J-4-i times longer. 

 Diameter oogon., 38-44 yw by 45-65 yw. 

 Diameter oospor. with spines, 37-42 yw by 43-55 yw. 

 Diameter androsp. cells, 17-18 u by 13-18 yw. 

 Diameter dwarf males, 10-11 ^ by 50-65 //. 

 Diameter sperm, cells, 7-8 yu by 10-14 /u. 



Eastern Pennsylvania. 

 Plate LXXXIV, fig. 8. 



SUBSECTION II. DICECIOUS, WITH ELONGATED MALE PLANTS ; 



MACRANDROUS. 



c. Oogonia not, or scarcely swollen. 



OEDOGONIUM CAPILLARE, (Linn.) Kg. 



Oogonia simple, not swollen, cylindrical, opening by a 

 pore above the middle ; oospore globose or cylindrical-glo- 

 bose (somewhat quadrangular in longitudinal section) not 

 filling the oogonium ; male plants the same or almost the 

 thickness of the female plants ; spermogonia 1-4 celled, 

 alternate with vegetative cells ; spermatozoids binate. 



Diameter veg. cells, 25-55 yu ; 1-2 times longer. 

 Diameter oogon. 25-55 yw by H times longer. 

 Diameter oospor. 22-52 /.i by 38-62 //. 

 Diameter sperm, cells, 24-48 jn by 5-6 //. 



