1889.] 184 [Seymour. 



nicht beobachtet. Oosporen unbekannt. Auf Blatten von Ribes 

 rubrum." 



The Minnesota specimens show conidia 1 1.7-1 7/u by 13-21// ; 

 oospores smooth or obscurely roughened, nearly filling the oogon- 

 ium and closely invested by its thin, fuliginous wall, 25.5 to 35.7/z. 

 The papilla of the conidium is seen with difficulty and appears more 

 like an inward thickening of the wall than as an external promi- 

 nence. On leaves of Ribes hirtellum. Detroit, Minn. 



Peronospora parasitica, (P.) Tul., on Lepidium; Jamestown, 

 Dak. 



Peronospora Arthuri, Farl., on Oenothera biennis; Sand Point, 

 Idaho. Oospores 15.6 to 39/z. 



Since this species was first published as occurring in Iowa and 

 Minnesota, it has been reported from Illinois, Wisconsin, Missouri, 

 Kansas and New York. To these localities may be added Nan- 

 tasket Beach, Mass., where it was found by the author, June 23, 

 1885 and Grand Manan, Aug. 13, 1888, K. Miyabe. 



Peronospora Trifoliorum, DBy. On Astragalus; Bismarck, 

 Dak., Livingston, Mont. 



Exs. : Fungi Europsei 3576. 



Cpstopus Bliti, (Biv.) Lev. On Amarantus retrojiexus ; St. Paul 

 and Brainerd, Minn., Jamestown, Dak. 



EEYSIPHE^i. 

 DETERMINED BY F. S. EARLE. 



SphcerotJieca Humili, (DC.) Burrill., on Viola; Valley City, Dak. 



Sphmrotheca pannosa, ( Wallr.) Lev., on Rosa; Valley City, Dak. 



SphcerotJieca Mors-uvaz, (S.) B. & C, on Ribes Jloriclum; Fargo, 

 Dak. 



Sphairotheca Castagnei, Lev., on Erechtites hieracifolia and Nab- 

 alus sp. Lake Minnetonka, Minn. Hydrophyllum Virginicum; 

 Valley City, Dak. 



Erysiphe communis, (Wallr.) Schl., on Ranunculus Cymbalaria; 

 Livingston, Mont. Lathyrus? ; Lake Minnetonka, Minn. Oeno- 

 thera biennis; Kootenai, Idaho. Oenothera sp. ; Bismarck, Dak. 



Erysiphe Cichoracearum, DC, on Aster, Valley City, Dak. 

 Solidago and Cnicus; Bozeman, Mont. Helianthus ; Fargo, Dak. 



Erysiphe Linkii, Lev., on Artemisia' dracunculoides ; Bozeman, 

 Mont. Artemisia sp. ; Valley City, Dak. Also on A. Ludoviciana ; 

 Helena, Mont., Sept., Rev. F. D. Kelsey. 



