LAGENIDIALES 951 



Olpidiopsis zopfii de Wildeman 



La Notarisia, 10 (3): 34. 1895; Ann. Soc. Beige Micro. (Mem.), 20: 26, pi. 1, 



figs. 1-3, 5-7. 1896 



(?) Pseudolpidiopsis zopfii (de Wild.) Minden, Kryptogamenfl. Mark Bran- 

 denburg, 5:259. 1911 (1915). 



Sporangium spherical or ovoid, with a single discharge tube, wall 

 thin, smooth, colorless, causing swelling of the infected cell; zoospores 

 not observed; resting spore spherical, thick-walled, 16-22 \x in diameter, 

 covered with numerous coarse sharp spines, germination not observed; 

 companion cells from one to three, spherical, 12 \x in diameter, with a 

 thin smooth colorless wall. 



In Spirogyra sp., coll. Massart, Belgium (Luxembourg). 



Olpidiopsis andreei (Lagerheim) Sparrow 

 Biol. Bulletin, 70: 245, text figs. 1-8, 12. 1936 



Pleotrachelus andreei Lagerheim, in Ymer, Tidskr. Svenska Sallskap. 



Antropol. Geogr., 19 (4): 436, fig. 1. 1899. 

 Bicilium andreei (Lagerheim) H. E. Petersen, Oversigt Kgl. Danske Vidensk. 



Selskabs. Forhandl., 1905 (5): 448, fig. I, 3-6. 

 Pleotrachelus ectocarpi Jokl. Osterr, botan. Zeitschr., 66: 267, pis. 4-5. 



1916. 

 Petersenia andreei (Lagerheim) Sparrow, be. cit. 



Sporangia from one to twenty-three in a cell, predominantly spher- 

 ical, 5-39 \x in diameter, or ellipsoidal and 8-15 by 15-25 \x, wall thin, 

 smooth, colorless, with from one to seven cylindrical radiating dis- 

 charge tubes up to 78 [x in length by 3-5 [jl in diameter; zoospores 

 irregularly pyriform, 4-5 [jl long by 3 \x wide, with a refractive area at 

 either end, anteriorly biflagellate, the flagella equal and oppositely 

 directed, initiating movement within the sporangium and escaping by 

 flagellar action through the open end of the discharge tubes, movement 

 erratic; resting spore spherical or ellipsoidal, 12-23 \x in diameter, with 

 a thick smooth brownish wall and contents with globules; companion 

 cell thin-walled, colorless, 4-8 [x in diameter, sometimes nearly as large 

 as the receptive thallus. 



In Spongomorpha sp., coll. Andre, Lagerheim (loc. cit.), King 

 Charles Land (Arctic); Acrosiphonia incurva, Acrosiphonia sp., A. 



