VAUCHERIA. 151 



oospores spotted with brown ; sporoderm very thick, com- 

 posed of several strata. Antheridia somewhat bag-shaped 

 or clavate, located near, or sometimes between two oogonia. 



Diameter of filaments and of oogonia, 50 ^ more or less. 



On damp or wet ground, shaded places, banks of rivers 

 and similar localities. 



Syn. V. pachyderma, Walz. ; V. Hookeri, Kg. ; V. Ungeri, Thnr. 

 Plate CXXVI, figs. 8, 9, 10, three sessile oogonia and 

 three antheridia. 



VAUCHERIA SESSILIS, ( Vauch. ) D. C. 



Loosely intricate, pale or dull green. Thallus capillary, 

 sparingly branched ; oogonia 2-3, approximate, rarely single, 

 ovate or oblong-oval, more or less oblique, rostrate ; anthe- 

 ridia intermediate, either short, hamate or straight and sub- 

 ulate, or a little clavate, sometimes elongated and incurved, 

 rarely circinate. Mature oospores punctate with brown, 

 involved in a triple membrane. 



Diameter of filaments about 50 IA. 



Rabenhorst describes five varieties of this species. 



l.--Var. sporangifera. Sporangia terminal, ovate- clavate. 



2.--Var. caespitosa, (Vauch. ) Ag. Oogonia usually twin, 

 ovate, with antheridia intermediate, sometimes 

 shortly uncinate. 



3. Var. ornithocephala, Hass. after Ag. Oogonia single or 

 twin, oblique rostrate; antheridia cylindrical-sub- 

 ulate, incurved, intermediate, longer than the 

 oogonia. 



4. Var. trigemina, Kg. Oogonia usually by threes. 

 5.- -Var. pphaerocarpa, Kg. A marine plant. 



Syn. Ectosperma sessilis, Vauch. ; Vauclieria caespitosa, Ag. ; 

 Vauch. ovoidea, Hass.; Vauch. Tovarensfa, Karst. 



Plate CXXVII, figs. 9-11, three ordinary forms of oogonia 

 and antheridia. 



VAUCHERIA GEMINATA, (Vauch.) D. C. 



Dark or dull green in dense intricate tufts. Filaments 

 capillary, tough, dichotomous. The fruiting on short lateral 

 branchlets, usually with two oogonia, opposite ; the anthe- 

 ridia between and extending above them, more or less re- 



