MONOBLEPH ARID ALES 727 



fertilization remaining in the oogonia or emerging, in either case devel- 

 oping into thick-walled oospores; oospore upon germination producing 

 a new thallus. 



Saprophytic primarily on vegetable debris, particularly twigs, and 

 on animal remains. 



The genus Diblephariswas established by Lagerheim to include Mono- 

 blepharis fasciculata and M. insignis Thaxter, which were described 

 as having biflagellate zoospores. See, however, the remarks under the 

 descriptions of these species (pp. 735, 737). 



Monoblephariopsis Laibach was erected to include Monoblepharis 

 regignens and M. ovigera, sporangial forms differing from other species 

 of Monoblepharis in having more slender hyphae and smaller sporangia, 

 which proliferated, and in lacking sex organs. 



KEY TO THE SPECIES OF MONOBLEPHARIS 1 



Sexual reproduction known; sex organs generally formed in abundance 



Oogonia without beaks, spherical, subspherical or narrowly pyri- 



form ; oospores exogenous, that is, extruded from the oogonium, 



or endogenous, that is, retained within the oogonium, generally 



spherical ; antheridia variously borne ; hyphae delicate, not often 



exceeding 5 [l in diameter; usually flexuous and much branched 



Oospores endogenous; antheridia hypogynous, that is, formed 



immediately below oogonium, usually strongly exserted... 



M. sphaerica, p. 728 



Oospores exogenous; antheridia variously borne 



Antheridia usually hypogynous, or on separate branches 

 Antheridia scarcely exserted, in young plants hypogynous, 



nearly always accompanying oogonia . . . M. hypogyna, p. 729 

 Antheridia conspicuously exserted, in young plants occurring 

 on separate branches from the oogonia, in older ones 

 formed in groups with the oogonia. 



Oospores bullate M. macrandra, p. 731 



Oospores smooth M. laevis, p. 733 



1 Perrott (1955) has taken up LagerheinVs (1900) division into the subgenera 

 Monoblepharis, containing the coarse endogenous species with cylindrical oogonia 

 (except M. sphaerica), and Exoospora, embracing the delicate exogenous forms with 

 more or less pyriform oogonia. To separate M. sphaerica in this manner from its 

 morphologically similar allies in the Exoospora seems somewhat extreme but may 

 prove practical. 



