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



p. 133, PI. XVI, fig. 91; P. B.-A., No. 813. Dioecious; 

 oogonia 2-6 or single, oboviform or oboviform-ellipsoid, pore 

 superior ; oospore globose or ellipsoid- globose, not filling or 

 nearly filling the oogonium, membrane double, outer membrane 

 pitted, inner smooth ; male plants about the same size as the 

 female ; antheridium 2-?-celled ; terminal cell, which sometimes 

 is an oogonium, obtuse. 



veg. cell, female, 25-38 M diam., 4-10 diani. loug. 



veg. cell, male, 26-33 /* " 4-9 " " 



oog., 70-83 /J. " 81-113 M long. 



oos., 58-65 M " 62-70 /j. " 



anth. cell, 24-32 /j. " 8-12 /u " 



Mass. So. America. 



25. OE. PUNCTATUM Wittrock, 1878, p. 142; Hirn, 1900, 

 p. 132, PI. XV, fig. 89. Dioecious; oogonia 2-4-seriate or 

 single, oboviform, rarely globose-oboviform, pore superior ; 

 oospore oboviform, almost filling the oogonium, rarely subglo- 

 bose, and then not filling the oogonium, membrane double, 

 outer membrane densely pitted, inner membrane smooth ; male 

 plants about the size of the female ; antheridia i-5-celled, 

 often alternating with the vegetative cells ; spermatozoids 

 binate, division horizontal ; basal cell elongate ; terminal cell, 

 which is frequently an oogonium, obtuse. 



veg. cell, female, 15-22 /udiam., 3-6 diam. long. 



veg. cell, male, 15-22 n " 3-6 " " 



oog., 38-45 fj. " 52-65 M long. 



oos., 37-43 M " 43-55 <" " 



auth. cell, 15-17^ " 6-10 M " 



Vera Cruz, Mexico. 



A species closely resembling this, Oc. scrobiculatum Wittr., 

 has been described from Equador ; the dimensions are somewhat 

 larger, the vegetative cells in the female plant ranging from 

 16-30 fj. ; the oogonia are usually solitary. 



26. OE. MARTINICENSE Hirn, 1900, p. 134, PI. XVI, fig. 92 ; 

 Oe. crassum Wolle, 1887, p. 74, PL L,XXVI, figs. 2 and 3. 

 Monoecious ; oogonia single, oboviform or suboboviform, pore 

 superior ; oospore oboviform or oboviform-ellipsoid, almost fill- 

 ing the oogonium, membrane smooth, usually rather thick ; 

 antheridia i-5-celled, hypogynous ; spermatozoids binate, divi- 

 sion vertical. 



veg. cell, 33-37 ^ diam., 3/^-6>^ diam. long, 



oog., 68-74 n " 96-124 ^ long, 



oos., 66-72 fj. " 81-96 M " 



anth. cell, 33-35 n " 5-7 M " 



Iowa, Kansas, Island of Martinique. 



