86 FRESH- WATER ALGJE OF THE UNITED STATES. 



Diameter oospor. with echinge, 70-75 jw by 70-75 yw. 

 Diameter androsp., 40-45 ^ by 10-12 //. 

 Diameter dwarf males, 15-18 u by 80-90 yw. 

 Diameter sperm, cells, 10-12 // 5-6 jw. 



Coll. Capt. J. Donnell Smith ; v. Bull. Torrey Bot. Club, 

 1879, p. 48. A very distinct species. 



Plate LXXXIY, figs. 3, 4, female filaments with oospores 

 and dwarf males ; fig. 5, male plant with androsporangia. 



OEDOGONIUM ECHINOSPERMUM, A. Br. 



Gynandrosporous or idio-androsporous ; oogonium single, 

 ellipsoid globose or snbglobose, opening by a pore in the 

 middle ; oospore globose, coated with subulate spines, filling 

 the oogonium ; androsporangia 2-5 celled ; dwarf males 

 rather short, curved, seated on the supporting cell; spermo- 

 gonia unicellular. 



Diameter veg. cells, 18-30 yw; 2]-4i times longer. 

 Diameter oogon. , 40-50 ^ by 42-57 /J. 

 Diameter oospor., 38-47 /* by 38-49 /w. 

 Diameter androsp. cells, 21-25 yu by 9-15 yw. 

 Diameter dwarf males, 10-12 /u by 30-35 //. 

 Diameter sperm, cells, 8-10 yw by 8-10 yw. 



Frequent in Pennsylvania, New York, New Jersey and 

 probably everywhere east of the Rocky Mountains. A 

 distinct form from Florida may be noted as 



Var. SPERMOGONIA MTJLTICELLTJLARIA, Wolle. 



Excels the ordinary form in fine development, larger size, 

 densely spinulose oospores and most prominent, the many 

 celled spermogonia. 



Plate LXXXIY, fig. 7, the ordinary form. 



Plate LXXXV, figs. 6-9, the new variety from Florida. 



OEDOGONIUM ECHINATUM, Wood, 



Gyiiandrous, very elongate ; joints 6-14 times longer than 

 broad ; sporangia globose, mostly depressed, about 35 ^ 

 diameter ; oospores of the same form as the sporangia whose 

 cavity they fill, covered with sharp spines ; the lateral pore 

 placed above the middle; antheridia bi- cellular. 



Dr. Wood remarks, "I found this distinct species in a 

 little stagnant pool, in Centre County, Pa. The filaments 

 are very long and were matted together into a sort of fibrous 

 mass. The male plants (dwarf males) were few in number 



