244 TUFTS COLLEGE STUDIES, VOL. II, No. 3 



veg. cell, female, 18-22 Mdiam., 2-6 diam. long. 



veg. cell, male, 16-19 /<. " 2-6 " " 



oog., 48-55 n " 38-48 M long. 



dbs., 40-51 M " 35-43 M " 



anth. cell, 16-19 M " 6-12 //, " 



basal cell, 28-31 /j. " 21-25 n " 



Greenland, Florida. Europe, So. America. 



Quite distinct from other American species, by the spiral 

 markings of the cell walls, as well as by other characters. The 

 Florida locality, Wolle's determination, is perhaps doubtful. 



33. OE. HOWARDII G. S.West, 1904, p. 281, PI. CCCCLXIV, 

 figs. 1-5. Dioecious; oogonia solitary, globose or subglobose, 

 operculate, division median ; oospore globose or sub-depressed- 

 globose, filling the oogonium ; antheridia pluricellular ; sper- 

 matozoid single ; vegetative cells slightly but distinctly capitel- 

 late ; basal cell of filament subhemispherical or subspherical, 

 not elongate. 



veg. cell, female, 9. 5-11 M diam. 2-4 diam long. 



veg. cell, male, 7-5-9 M " 2-4 " " 



oog., 29-33 M " 29-33 M long. 



oos., 25-29 //, " 25-29 n " 



anth. cell, 7.5-9 M " 8-14/4 " 



basal cell, 14-16/1 " 10-11 /x " 



Barbados. 



With basal cell similar to Oe. pundato-striatum, but smaller 

 in all dimensions, and without the spiral markings of the latter 

 species. 



34. OE. PITHOPHORAE Wittrock, 1878, p. 141 ; Him, 1900, 

 p. 157, PI. XXIV, fig. 134. Monoecious ; oogonia single, pyri- 

 form-globose, operculate, division superior; oospore globose, 

 almost filling the oogonium, membrane smooth, often thickish ; 

 antheridia i (or more ?)-celled, subepigynous ; basal cell elon- 

 gate. 



veg. cell, 9-11 M diam., 2^-4^ diam. long, 



oog., 26-30 M " 27-35 /* long. 



OOS., 25-29 /x " 24-29 fJ. " 



anth. cell, 8-10 /u " 7-9 /x " 



St. Thomas, W. I., epiphytic on Pithophora Cleveana. 



35. OE. CRISPUM (Hass.) Wittrock, 1874, p. 10 ; Wolle, 

 1887, p. 72, PI. LXXIV, figs. 11-15; Hirn, 1900, p. 159, PI. 

 XXV, fig. 138; Wittr. and Nordst., Alg. Exsicc., Nos. 209, 

 508 ; Tilden, American Algae, No. 543. Monoecious ; oogonia 

 single, very rarely 2, oboviform-globose, operculate, division 



