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



The net-like marking of the spores is found in some other 

 species, but the only one with which there is any danger of mis- 

 take is Oe. scrobiculatum , which can be distinguished by being 

 dioecious, and having ellipsoid spores. 



14. OE. GENICULATUM Him, 1898, p. 28 ; 1900, p. 106, PI. 

 VIII, fig. 48 ; P. B.-A., No. 411. Monoecious ; oogonia single, 

 slightly swollen, oboviform or oboviform-globose, pore superior; 

 oospore not filling the oogonium, globose or sub-depressed- 

 globose, sometimes appearing subquadrangular ; membrane 

 thick, smooth; antheridia i-5-celled, subepigynous, subhypo- 

 gynous or scattered, often alternating with vegetative cells. 



veg. cell, 37-48 M diatu., 1^-3 diam. long. 



oog., 56-63 fj. "' 56-67 fj. long. 



oos., 48-59 n " 48-59 M " 



anth. cell, 37-44 fj. " 5-9 /u " 



California. 



Noticeable in this species is the fact that the oogonia' pro- 

 ject but little beyond the vegetative cells ; a few other species 

 are similar, but they are all dioecious. 



15. OE. CAPILLIFORME Kiitzing, 1849, p. 367 ; Wolle, 1887, 

 p. 88, PI. LXXV, figs. 11-13; Him, 1900, p. 107, PL VIII, 

 fig. 49; Roumeguere, Alg. Exsicc., No. 685, as Oe. capillare. 

 Dioecious ; oogonia single, slightly swollen, oboviform or sub- 

 oboviform, pore superior ; oospore ellipsoid-globose or cylin- 

 drical-globose and appearing quadrangular, sometimes with a 

 slight constriction at the middle, more rarely globose or sub- 

 globose, not filling the oogonium, membrane smooth ; male 

 plant slightly more slender than the female ; antheridia 2-5-, 

 rarely lo-celled, often alternating with the vegetative cells ; 

 spermatozoids binate, division horizontal ; basal cell elongate, 

 terminal cell obtuse or apiculate. 



veg. cell, female, 28-38 ^ diam., iK-3 diam. long, 



veg. cell, male, 25-30 M " 1^-3 " " 



oog., 42-50 M " 51-62 /x long, 



oos., 37-45 /j. " 40-50 /j. " 



anth. cell, 20-25 /u " 8-10 M " 



Reported by Wolle, but questioned by Hirn as to being of the 

 type. From St. Louis, Mo., is recorded a forma valida, one- 

 seventh to one-tenth larger. 



Var. AUSTRALE Wittrock in Wittr. and Nordst., Alg. Exsicc., 

 No. 704; Hirn, 1900, p. 109, PI. IX, fig. 52; P. B.-A. % No. 

 1189; Oe. princeps Wolle, 1887, P- 93- PL IvXXVIII, fig. 3 ; 



