256 



TUFTS COLLEGE STUDIES, VOL. II, No. 3 



veg. cell, 

 suf. cell, 

 oog., 

 oos., 



andr. cell, 



nail, stipe, 



anth. cell, 



Mass., Pa., Cal. 



A common species 



!5- 2 3 M diam., 

 31-38 /* " 

 40-50 M " 

 35-46 AI " 

 16-19 M " 

 12-15 /" " 



3-6 



diatu. long. 



" 

 M long. 



55-90 



48-60 tt " 



15-23 /x " 



35'47 -" " 



7-10 M " 11-15 M " 



Europe, Australia, So. America. 



distinguished from Oe. crassiusculum by 



the much swollen cell below the oogonium ; the cells are rela- 

 tively slender just above the oogonium, and increase rapidly 

 and uniformly to and including the oogonium ; above this the 

 cell is slender again ; from the two following species, Oe. Wolle- 

 anum and Oe. concatcnatum, it is distinguished by the oospore 

 being smooth, not striate. 



57. OE. WOLLEANUM Wittrock, 18783, p. 137 ; Wolle, 1887, 

 p. 82, PI. L,XXX, figs. 4 and 5 ; Him, 1900, p. 220, PI. 

 XXXVII, fig. 226 ; Wittr. and Nordst., Alg. Exsicc., No. 107. 

 Dioecious, nannandrous, gynandrosporous or idioandrosporous ; 

 oogonia single or 2, more rarely 3-4, suboboviform or quadran- 

 gular-ellipsoid, pore superior, membrane with raised longitud- 

 inal lines on the inner surface ; oospore same form as the oogo- 

 nium, quite filling it, membrane double ; external membrane 

 with 25-35 longitudinal raised lines, rarely anastomosing ; inner 

 membrane smooth ; suffultory cell swollen ; androsporangia 1-3- 

 celled, often subepigynous, or scattered in the upper part of the 

 filament ; basal cell elongate ; terminal cell, which is some- 

 times an oogonium, short acute or acuminate ; dwarf males on 

 suffultory cell, stipe slightly curved ; antheridium exterior, 1-3- 

 celled. 



veg. cell, 

 suf. cell, 

 oog., 

 oos., 



andr. cell, 

 nan. stipe, 

 anth. cell, 

 Greenland, Mass 



21-30 fj. diam. 



45-56 M " 



58-68 fj. " 



56-66^ " 



21-30/4 " 



15-24 /x " 



9-14 M " 



3-8 diaui. long. 



^-2 



long. 



69-89 



65-83 M " 



18-25 M " 



54-60/1* " 



7-11 M " 

 Conn., N. J., Pa., Minn., Fla. 



Europe, Asia, So. America. 



A cosmopolitan species, and generally quite uniform in its 

 characters; it is distinguished from Oc. Bonsiamim and Oe. con- 

 catcnatum by the lines on the oogonium and the oospore, the 

 two fitting closely, the elevations on one into the furrows in 



