142 a rE -OXE DOG ONT ACE ACE 
164. Oe. oelandicum Wittrock; Hirn. 
(Pl. LVI, fig. 539.) 
Wittrock 1874, p. 17; Hirn 1900, p. 273, Pl. XLVII, fig. 297. 
Dioecious, nannandrous, gynandrosporous; oozonium 1-7, depressed- 
globose, with 12-16 longitudinal ridges, operculate, division supra- 
median, rather broad; oospore depressed-globose, nearly filling oogonium, 
spore wall smooth; androsporangium to 6-seriate; vegetative cell 
capitellate; terminal cell apically obtuse; dwarf male obovoid, uni- 
cellular, on oogonium; vegetative cell 10-15%25-125u; oogonium 
31-40 25-324; oospore 25-36 23-30u; androsporangium 7-12 
10-184; dwarf male 7-8 X 12-15u. 
United States: Michigan; British Columbia; Sweden. 
164a. Form minus Borge. 
(Pl. LVI, fig. 540.) 
LORE pe 20a, ble 2) feel: 
Smaller; vegetative cell 9-1036-50u; oogonium 27-30 X 19-25n; 
dwarf male 6-7 X 11-12u. 
The species is characterized by its longitudinally ridged 
oogonia, supramedian operculum, and capitellate vegetative 
cells. It is smaller than the similarly appearing, larger Oe. 
megaporum, below. F. minus has shorter oogonia. 
165. Oe. megaporum Wittrock. 
(Pl. LVI, fig. 543.) 
1872, p. 3, Pl. 1, figs. 6 and 6; Hirn 1900, p. 274, Pl. XLVII, figs. 298 and 299; 
Oe. oelandicum Wittr. var. subpyriforme Wittr. i Wittr., Nordst., and Lagerh. 
Alg. Exs. No. 1218, 1896. 
Dioecious, nannandrous, idioandrosporous; oogonium 1-6, broadly 
pyriform, with 12-16 rounded longitudinal ridges, operculate, division 
supramedian and wide; oospore subdepressed-globose, not filling 
oogonium, spore wall smooth; androsporangium to 4-seriate; vegetative 
cell capitellate, basal cell elongate; terminal cell apically obtuse; dwarf 
male unicellular, broadly obovoid, on oogonium; vegetative cell 13-17 X 
40-100u; oogonium 37-4240-45u; oospore 31-35 (-38)X27-30y; 
androsporangium 10-11 12—22u; dwarf male 8-12X 13-16n. ; 
United States: Michigan; Finland, Germany, Sweden. 
Cf. Oe. oelandicum (No. 164). 
166. Oe. bahusiense Nordstedt. 
(Pl. LV, figs. 530 and 531.) 
1877, p. 26, Pl. 3, figs. 7-11; Hirn 1900, p. 279, Pl. XLVIII, fig. 307. 
Dioecious, nannandrous, gynandrosporous; oogonium 1 (rarely 2), 
depressed pyriform, with 9-12 longitudinal ridges appearing as a median 
whorl, operculate, division inframedian; oospore depressed-obovoid or 
depressed-globose, nearly filling oogonium, spore wall smooth; andro- 
sporangium to -+-seriate, scattered, often terminal; vegetative cell 
