142 THE NORTH AMERICAN SLIME-MOULDS 



Rare on rotten logs in the forests; September. Easily recognized 

 by the short-stiped, ashen sporangia which before dehiscence indicate 

 by delicate tracings the lines which subsequent cleavage is to follow. 

 In texture the peridium resembles that of D. fioriforme. 



Pennsylvania, Ohio, Iowa, Virginia, Colorado, Washington, 

 Oregon ; Europe generally. 



The Linnaean description on which to base the specific name 

 D. radiatum is wholly inadequate. It appears also by the testimony 

 of Linne fils, that L. radiatum Linne is a lichen ! and the name is so 

 applied by Persoon. But in the Linnasan herbarium preserved at 

 London, teste Lister, the original type of Lycoperdon radiatum L. 

 may yet be seen ! to the confusion of fils, Persoon, and other followers 

 of Schrader all, and our stellar species becomes radiate now, let us 

 hope for long! 



16. DiDERMA TREVELYANI (Grev.) Fr. 



1825. Leangium trevelyani Grev., Scot., Cr. FL, Tab. 132. 



1829. Diderma trevelyani (Grev.) Fr., Syst. Myc, III., p. 105. 



1875. Chondrioderma trevelyani (Grev.) Rost., Mon., p. 182. 



1877. Diderma geasteroides Phill., Grev., V., p. 113. 



1877. Diderma laciniatum Phill., Grev., V., p. 113. 



Sporangia scattered, globose or nearly so, smooth or verruculose, 

 reddish-brown or rufescent, sessile or short-stipitate, the outer perid- 

 ium firm, splitting more or less regularly into unequal, revolute, 

 petal-like lobes which are white within, the inner not distinguishable 

 as such ; stipe, when present, equal, furrowed, concolorous ; columella 

 small or none; capillitium abundant, the threads rather rigid, purple 

 or purplish brow^n, branching and anastomosing, more or less beaded ; 

 spores dark, violaceous brown, spinulose, 10-13 fi. 



In 1876, Harkness and Moore collected in the Sierra Nevada 

 Mountains of California, forms of Diderma which are described by 

 Phillips, Grev., V., p. 113, as D. geasteroides and D. laciniatum. 

 English authorities who have examined the material agree that the 

 forms described constitute but a single species, and Lister makes them 

 identical with D. trevelyani (Grev.) Fr. Rostafinski's figures, 161, 

 162, are a curious reproduction, evidently, of Fried. Nees von Esen- 

 beck's, Plate IX., Fig. 4. Massee describes a columella; Lister says 



