The Myxomycetes of the A/iaini I'alley, Ohio. 137 



mon hypotliallus, the apices of the final branches coherent at 

 the surface, and naked or covered by an additional corticate 

 layer. Walls of the sporangia consisting of a thin menibrane, 

 with abundant fibrous thickenings, presenting broad expan- 

 sions, narrowing to thin flat bands, and reduced in many 

 places to slender fibrous threads. Spores abundant, globose, 

 umber or violaceous. 



After the maturity of the spores disintegration of the spor- 

 angial wall begins, the thin membrane disappearing more 

 rapidly than the fibrous thickenings or the portions of the 

 sporangial walls near the base, which are more compactly 

 grown together; there is thus left at each stage an increasing 

 number of the shreddy fibers mingled with the spores. 



1. Reticularia splendens, Morg. n. sp. ^thalium 

 pulvinate, circular or more or less elongated and irregular, 

 seated on a conspicuous silvery hypotliallus ; the surface 

 naked, bright umber, smooth and shining. Walls of the 

 sporangia firm and quite persistent, pale umber, slowly disin- 

 tegrating, consisting for the most part of wide expansions, 

 with their angles tapering to narrow bands and slender 

 threads. Spores in the mass pale umber, globose, most of 

 the surface reticulate, 7-9 mic. in diameter. See Plate III, 

 Fig. 10. 



Growing on old wood, .^thalium from i to several centi- 

 meters in extent and 5-10 mm. in thickness, usually growing 

 singly, rarely close enough to be confluent. This species has 

 lately been referred to Reticularia rozeana, Rost., but it varies 

 greatly from the account given of that species in the Journal 

 of Botany for September, iSgi. 



2. Reticularia umhrina. Fr. ^thalium pulvinate, 

 roundish, more or less irregular, the surface covered by a 

 thin, silvery, shining, common cortex, which at the base is 

 confluent with the hypotliallus. Walls of the sporangia 

 umber or rusty-brown next the base, with broad expansions 

 in places thickly grown together, toward the surface passing 

 into narrow bands and abundant fibrous threads, which 

 rapidly disintegrate. Spores in the mass umber or rusty 

 brown, globose, most of the surface reticulate, 7-9 mic. in 

 diameter. 



