STEMONITACE^E IO/ 



calcareous deposits withal, tapering upward, and continued 

 within the peridium as a pronounced more or less calcareous 

 columella ; hypothallus more or less prominent, yellowish or 

 brownish ; capillitium dark purplish brown, of sparingly branch- 

 ing threads radiating from the columella ; spores dull purplish 

 brown, minutely roughened, 10-12 /u,. 



A singular species, rare, but easily recognized by its peculiar, 

 placoid scales, large and firmly embedded in the peridial wall. 

 The internal structure is essentially that of Diderma or Didym- 

 ium. The species occurs in hilly or mountainous regions, on 

 moss-covered logs. The plasmodium pale yellow, and some 

 part of it not infrequently remains as a venulose hypothallus 

 connecting such sporangia as are near together. 



New York, Pennsylvania, New England, Missouri, Iowa ; 

 Black Hills, South Dakota, Washington. 



ORDER II. 

 STEMONITACE^:. 



Capillitium present, thread-like, arising in typical cases from a 

 well-developed columella ; spores in mass, black or violet brown, 

 more rarely ferruginous. 



Key to the Families of Stemonitacese. 



A. Fructification aethalioid, capillitium poorly defined; columella rudi- 



mentary or none AMAUROCH/ETE^E 



B. Fructification aethalioid, or of distinct sporangia, capillitium well de- 



fined ; the columella generally prominent, long and abundantly 

 branched throughout STEMONITE^E 



C. Sporangia distinct ; capillitium developed chiefly or only from the 



summit of the columella .... LAMPRODERMEYE 



A. AMAUROCH^ETE^:. 



Fructification gethalioid, an inch or two in diameter, in form 

 varying with the habitat, developed from a plasmodium at first 

 white, then yellow, passing through various tints of brown, at 



