36 LHE: OED OGON 1A CEASE 
Hirn. I have seen a great number of intermedia plants from 
the North Central states, and judging from this American 
material and from original descriptions, it seems almost impos- 
sible to recognize with certainty either of the two forms above; 
the variety is probably distinct. Occasionally individual plants 
and more often parts of filaments are found with slight differ- 
ences and variations in form and shape of vegetative cells and 
oogonia. Frequently all variations between the type and the 
two forms can be noted in one plant. The variety depressa 
with relatively longer cells in proportion to diameter is perhaps 
sufficiently distinct to recognize. It does not appear to be to 
the best interests of taxonomic nomenclature in this species to 
do little more than recognize its variability. I have, therefore, 
included with the species proper the two forms americana and 
supramediana. The relationship to B. crenulata is noted above, 
under that species. 
13. B. subintermedia Elfving. 
(Pl. Il, fig. 15.) 
In Hirn 1895, p. 8; Hirn 1900, p. 332, Pl. LIII, fig. 338; Heering 1914, p. 233, 
fig. 360; West 1916, p. 396, fig. 251A; Tiffany 1928, p. 188, Pl. XV, fig. 15. 
Dioecious, nannandrous, gynandrosporous; oogonia subdepressed- 
globose, patent, below terminal setae, androsporangia, or rarely vege- 
tative cells; division of suffultory cell submedian; outer spore wall 
scrobiculate; androsporangia 1—’, epigynous or scattered; dwarf males 
on oogonia, stipe curved or nearly erect, shorter than the oogonia; 
vegetative cells 17-2234-100u; oogonia 44-51 X39-44y; oospores 
42-48 X37-41u; androsporangia 13-16X9-10u; dwarf males 10-12 
25-30u. 
Finland, Great Britain. 
14. B. angulosa Wittrock and Lundell. 
(PEST ig. 143) 
In Wittrock 1874, p. 45; (?) B. elachistandria Wittr. in Wolle 1887, p. 97; Hirn 
1900, p. 336, Pl. LIV, fig. 346; Heering 1914, p. 235, fig. 364; Tiffany 1928, p. 138, 
Pl. XV, fig. 14. 
Dioecious, nannandrous, gynandrosporous; oogonia biconically and 
angularly globose, apically truncate, below terminal setae or rarely 
androsporangia; division of suffultory cells a little above median position; 
oospore wall smooth; androsporangia scattered or epigynous, 1-3; 
dwarf males on oogonia, antheridia interior, stipe somewhat curved; 
vegetative cells 13-18X20-45yu; oogonia 36-42X33-39u; oospores 
34-40 X 30-364; androsporangia 10-11X9-10u; dwarf males 8-9X 
18-21. 
United States: Pennsylvania; England, Sweden, Finland, 
Africa. 
