21-1 MICROSCOPIC FUNGI. 



Melampsora Tremulge, Tul. Ilypophvllous ; sori of 

 summer spores punctifonii, prominent, or papilleeform, numerous ; 

 spores tawny-yellow, elliptical orobovate; paraphyses slender; 

 son of perfect spores scattered, at length blackish; spores 

 elongated, compressed, attenuated downwards, yellowish.— On 

 leaves of Fopulus tremula. Conmion. Spores perfected duriug 

 the winter. 



Melampsora Betulina, Desm. Hypophvllous ; sori of 

 summer spores bright yellow or orange, oblong," cylindrical, or 

 obovate, truncate at the base, echinulate ; paraplivses encircling 

 or mtermixed, obovate, smooth, hyaline ; sori of 'perfect spores 

 confluent, of an obscure brown in the winter, becoming of a bright 

 orange when mature ; spores elongated, attenuated below, poly- 

 gonal, ochraceous.— On leaves of Betula alba. Common. Spores 

 perfected in January and February. (Plate IX. figs. 189, 190.) 



Melampsora Salicina, Lev. Epiphyllous or hypophyllous ; 

 sori, or heaps of summer spores, scattered, pale orange, bright 

 orange, or .cmereous ; spores ovato-globose, paraphyses capitate^ 

 rarely obovate ; sori of perfect spores epiphyllous, scattered or 

 aggregate, at first yellowish-tawny, then bro^vnish, at length 

 nearly black, buUate ; spores oblong, closely packed, and laterally 

 compressed.— On Salix viminalis and S. capraa. Common. Spores 

 perfected in February. (Plate IX. figs. 191, 192.) 



Cystopus. 



Receptacle consisting of thick branched threads ; conidia con- 

 catenate, at length sepai-ating ; oospores deeply seated on 



f the mycelium. 



Cystopus candidus, Lev. Cruciper White Eust; 

 conidia equal, globose; membrane equal, ochraceous; oospores 

 subglobose, epispore yellowish-brown, with in-egular obtuse 

 warts ; warts solid.— On Shepherd's-purse, Cabbages, and other 

 Cruciferse. Summer. Very common. (Plate X. figs. 198—200, 

 205-207.) ^ V a , 



Cystopus eubieus, Str. Goatsbeard White Eust; 

 conidia unequal ; terminal cell sterile, larger than the rest ; 

 membrane thickened, ochraceous, rarely yellowish ; fertile cells 

 shortly cylindrical ; membrane hyaline; oospores globose ; epispore 

 brown, verrucose; warts hollow, round, or irregular.— On goats- 

 beard, salsify, and scorzonera. Summer and autumn. Common. 

 (Plate X. figs. 201, 202, 210.) 



Cystopus Lepigoni, De By. Sandwort White Rust; 

 conidia unequal ; terminal cell sterile, globose ; membrane 

 thickened; fertile cells subglobose or cylindrical; membrane 

 hyaline ; oospores globose ; epispore brown, tubercles minute, 

 irregular, very convex, often resembling spines. — On Sperguiaria 

 rubra. Swanscombe Marshes, September, 18C4. (B. G. Keek]/.) 



