210 THE NORTH AMERICAN SLIME-MOULDS 



Plasmodium at first white, then pink, 'ashes of roses,' etc. Sporan- 

 gia wholly indeterminate or undefined, their walls represented ( ?) by 

 a spongy mass of so-called capillitium, consisting of membranous 

 plates, branching, anastomosing, vanishing without order or sym- 

 metry, generally giving rise at the sides, and especially above, to long 

 slender ficxuous threads; outer cortex silvery white; hypothallus dis- 

 tinct, white; spore-mass and threads umber or rusty brown. 



A single species, — 



1. Reticularia lycoperdon (Bull.) Rost. 



Plate X,, Figs. 7, 7a; Plate XII., Fig. 3. 

 1791. Reticularia lycoperdon Bull., Champ, de la France, p. 95. 



vEthalium pulvinate, 2-8 cm. broad, at first silvery white, later 

 less lustrous, the cortex irregularly and slowly deciduous; hypothallus 

 at first conspicuous as a white margin extending round the entire 

 aethalium, evanescent without, but persisting as a firm membrane 

 beneath the spore-mass, pseudo-capillitium abundant, tending to form 

 erect central masses which persist long after the greater part of the 

 fruit has been scattered by the winds; spore-mass umber, spores by 

 transmitted light pale, reticulate over about two-thirds of the surface, 

 the remainder slightly warted, 8-9 fi. 



Not common. Often confused with the following, the spores 

 of the two forms being very much alike ; the internal structure, entire- 

 ly different, and once compared, the two are thereafter easily dis- 

 tinguished at sight by external characters. The sporangial make-up 

 is indifferent, confused. It represents a phase in development whence 

 might issue columellae with capillitium-branches or distinct tubular 

 sporangia with persisting walls; or are such structures here but rem- 

 iniscent only? Compare Amaurochaete atra, where similar con- 

 ditions prevail. There differentiation goes on to the formation of a 

 structure of which Sternonitis is type; here the sporangium-wall be- 

 comes dominant; suffers modification for spore-disposal, an idea reach- 

 ing fair expression in Cribraria and Dictydium. 



The Plasmodium is \\hite, noted Bulliard. Fries cites with ap- 

 proval the words of Schweinitz, — "color corticis ab initio argenteus 



