MUSHROOMS AND TOADSTOOLS 245 



Peridium opening by a deciduous membrane — 



Sporangioles attached to the inner wall of the peridium — 

 Peridium of three united layers and spores mixed with 



filaments Cyalhua. 



Peridium of a single layer and spores not mixed with 



filaments Crudbnlmn. 



Cyathus 



In Cyalhiis the peridium is cup-like and composed of three layers. 

 The apex is covered by a white membrane, which bursts, disclosing egg- 

 like bodies, the peridiola, which usually fill about one-half of the cup. 

 The peridiola are attached to the inner wall of the peridium by an elastic 

 cord, which is attached to each peridiolum in a depression on one side. 



Cyathus stercoreus 



Peridium cylindrical, campanulate to infundibuliform, sessile or with an elon- 

 gated base, light brownish, at first with shaggy, matted hairs which disappear in age, 

 interior smooth and nonstriate; peridiola black. 



Cyathus skrcoreus is an exceedingly common species and is to be found growing 

 on manure or in heavily manured places. It is subject to considerable variation in 

 size and form. 



Cyathus striatus 



Peridium obconic, exterior even, brownish, hairy, interior striate, lead-colored; 

 apex truncate, covered by a white membrane, which is at first strigose; peridiola 

 compressed, subcircular. 



Plant one-half to three-fourths inch in height and about three-eighths inch in 

 diameter. 



Cyathus vernicosus 



Peridium bell-shaped, subsessile, base narrow, broadly open above, exterior at 

 first brownish, silky tomentose, becoming smooth, interior dull lead color, smooth. 

 Differs from Cyathus striatus in the even, non-fluted inner surface of the peridium and 

 in the larger peridiola. 



Plant about one-half inch in height and about three-eighths inch in diameter. 



Crucibulum 



In Crucibulum the peridium is cup-shaped and consists of one thick 

 fibrous layer, Hned by a very thin, smooth, and shining layer. The 



