BOTANICAL GAZETTE. 



315 



which were brown, thin-walled and considerably smaller than the oogonia. The 

 rigidity of the oogonium wall and other characters given above lead me to 

 place the speeies in the present section, although it approaches the section 



B. CHothecce. Wall of oogonium thin, wrinkled at maturity. Exospore 

 not smooth, but regularly tuberculose, verrucose, or reticulated. Haustona 

 filiform, branching. 



12. P. Myosotidts DeBary. 



DeBarv 1. c. p. 108. PI. XIII, f. 5 ; Rabh. Fung. Eur. 57:2. 



Conidiophores long, slender, several times dichotomous, ulti- 

 mate divisions slender, widely spreading. Conidia ovate-obtuse 

 20-23;/. by 15-18//, faintly violet colored. Oospores rather small, 

 24-30// in diameter, dark brown, exospore marked with regular 

 reticulations. 



On Myosotis verna. 



Chebacco Lake, Mass. (Seymour), Cobden, 111. (Earle). Europe. 



Found on the leaves, especially the lower ones, in spring. Apparently not 

 common. Recognized by the beautifully reticulated oospores which accompany 

 the conidia in all the American specimens I have examined. 



13. P. Arthuri n. sp. 



Conidiophores rather short and rigid, several times dichoto- 

 mous. Tips rather short and rigid. Conidia broadly ellipsoidal, 

 obtuse, 22-26,^ by 19//, slightly violet-colored. Oospores large, 

 dark brown, 34-42// in diameter, exospore covered with short 

 blunt papillre. 



On (Enothera biennis. 



Iowa (Arthur), Minnesota (Farlow). 



This species, first detected by Prof. Arthur in Iowa, was found abundant on 

 the shore of Lake Minnetonka, Minn. The fungus covers the under surface of 

 the leaves in large patches, and the upper side of the leaves becomes pale yel- 

 low. The species is quite distinct from /'. Epilobii Rabh., the conidiophores of 

 which, as shown by Fung. Eur. no. 1747, are rather of the pinnate type, and 

 whose conidia are not violet colored, but white. The papillate oospores also 

 serve to distinguish the present from our other species. A form of Peronospora 

 on (Enothera from New York is referred by Peck in his 30th Report to P. effusa. 



14. P. Vici.e (Berk.) DeBary. 



This species, closely related to P. Myosotidis, and common in Europe on 

 Papilionacecr, is reported by Harkness and Moore to occur on pear leaves in Cal- 

 ifornia. It may, perhaps, be asked whether this is not a misprint for pea leaves. 

 Certainly the species is not known elsewhere on pear leaves. 



[ TO BE CONTINUED.] 



