LEPTOMITALES 887 



merits by constrictions (pseudosepta). Sporangia formed singly or in 

 clusters terminally or sub-terminally, pedicellate, hyaline, obpyriform 

 when young, elongate-clavate when mature, thin and smooth-walled, 

 80 ■: 23, (21-144 14—30) [jl. Oogonia and anthcridia borne on sep- 

 arate thalli; oogonia obovate or spherical, pedicellate; antheridia 

 pedicellate, irregularly clavate, 19 9.5 u.; oospore one in each oogo- 

 nium, spherical with a thick reticulately sculptured wall, 28-32 u. in 

 diameter" (Iyengar, Ramakrishnan, and Subramanian, he. cit.). 

 On dead leaves, India. 



EXCLUDED SPECIES OF SAPROMYCES 



* Sapromyces dubius K. Fritsch 



Osterr. botan. Zeitschr., 43: 421. 1893 



See page 885. Based upon a fragment of a Rhipidium (Reinsch, 1878; 

 pi. 15, figs. 7-11). 



ARAIOSPORA Thaxter 



Bot. Gaz., 21: 326. 1896 



(Fig. 70 C-H, p. 890) 



Rhipidium Cornu, pro parte, Bull. Soc. Bot. France, 18: 59. 1871. 



Thallus differentiated into a well-defined epibiotic basal cell and, 

 arising from this, numerous repeatedly umbellately branched more or 

 less segmented and constricted cylindrical filaments on which are borne 

 the reproductive organs, the whole anchored to the substratum by a 

 complex of endobiotic branched holdfasts; zoosporangia formed in 

 whorls or umbels at the tips of the segments, from which they are 

 separated by a constriction, wall smooth or spiny; zoospores reniform, 

 laterally biflagellate, contents finely granular, fully formed within the 

 sporangium, emerging upon the deliquescence of an apical papilla, 

 often surrounded by a quickly evanescent vesicle; antheridium borne 

 at the tip of a branched or unbranched specialized segment; oogonia 

 spherical, monandrous, borne in whorls or umbels on short lateral 

 constricted segments, the contents at maturity differentiated into 

 ooplasm and periplasm; oospore borne singly in the oogonium, thick- 



