Plasmodium at first white, then pink, 'ashes of roses,' etc. Sporangia 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 symmetry, generally giving rise at the sides, and especially above, to long slender flexuous threads; outer cortex silvery white; hypothallus distinct, white; spore-mass and threads umber or rusty brown. A single species,-- 1. RETICULARIA LYCOPERDON (_Bull._) _Rost._ PLATE X., Figs. 7, 7 _a_; PLATE XII., Fig. 3. 1791. _Reticularia lycoperdon_ Bull., _Champ. de la France_, p. 95. Aethalium 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 mu. Not common. Often confused with the following, the spores of the two forms being very much alike; the internal structure, entirely different, and once compared, the two are thereafter easily distinguished 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 reminiscent only? Compare _Amaurochaete atra_, where similar conditions prevail. There differentiation goes on to the formation of a structure of which _Stemonitis_ is type; here the sporangium-wall becomes dominant; suffers modification for spore-disposal, an idea reaching fair expression in _Cribraria_ and _Dictydium_. The plasmodium is white, noted Bulliard. Fries cites with approval the words of Schweinitz,--"color corticis ab initio argenteus sericeo nitore insignis; sed deinde sordescit e griseo in subfuscum vergens." Sometimes the surface does indeed shine as silver! The fructification appears to be isolated in each case; the entire plasmodium consumed in a single plasmodiocarp. Widely distributed. Maine to California, and south. =2. Enteridium= _Ehrenberg_ 1818. _Enteridium_ Ehrenberg, Link and Spreng., _Jahrb., Bd._ II., p. 55. Fructification aethalioid; the confluent sporangia inextricably interwoven, the walls perforate by large openings, the resultant network of broad plates and bands widening at the points of intersection.