DIDERMA 137 



rangia and pink lime deposits. The var. macrosporum Meylan (Bull. 

 Soc. Vaud. Sc. Nat. 56 : 68, 1925) is said to have spores 14-15 fi. 



Pennsylvania, Virginia, Ohio, Iowa, Colorado, Montana, Washing- 

 ton, Oregon; Europe generally, North Africa, Australia, India, Japan. 



22. Diderma roanense (Rex) Macbr. 



N. A. Slime-Moulds 104. 1899. 

 PI. IX, Figs. 206, 207. 



1893. Chondrioderma roanense Rex, Proc. Ac. Nat. Sc. Phila. 368. 



Sporangia scattered, discoidal, thin, flattened or slightly convex 

 above, plane or plano-concave below, umber-brown, stipitate, the outer 

 peridium smooth, brittle, rupturing irregularly, the basal fragments 

 somewhat persistent, concrete with the inner peridium, which is pure 

 white, except near the columella, and punctate; stipe short, variable, 

 longitudinally ridged, jet-black; hypothallus not evident; columella 

 flat, discoidal, pale ochraceous; capillitium sparse, white or colorless, 

 composed of simple, rarely forked, sinuous threads occasionally joined 

 by lateral branches; spores dark violaceous, minutely but distinctly 

 warted, 12-14 ju. 



This species is readily distinguished by its color. The sporangia, 

 found on rotten wood, are large, 1 mm. in diameter, brown, and have 

 thick, persistent walls. Doctor Rex considered that the species differs 

 from other related forms not only in color, but in the well-marked 

 discoidal columella and the jet-black irregular stipe. It is perhaps 

 most nearly related to D. radiatum. 



Maine, New Hampshire, Tennessee, Colorado; Switzerland. 



23. Diderma lucidum Berk. & Br. 



Ann. Mag. Nat. Hist. 3 ser. 7 : 380. 1861. 



1877. Chondrioderma lucidum (Berk. & Br.) Cooke, Myx. Gt. Brit. 42. 

 1892. Chondrioderma carmichaelianum (Berk.) Cooke ex Mass., Mon. 202, in 

 part. 



Sporangia scattered, subglobose, flattened beneath, 0.8 mm. in 

 diameter, usually stalked, orange or vermilion, glossy, with pitted 

 surface, dehiscing irregularly or by four or five lobes that become pale 

 at the margins; outer layer of sporangium wall translucent orange- 

 yellow, with scanty deposits of lime on the inner side, closely con- 

 nected with the yellow inner layer; stalk slender, subulate, brownish 

 black, 0.2-0.5 mm. high; columella obconic or subglobose, often short- 

 stalked, rugose, white or cream colored, filled with lime granules; 

 capillitium a scanty and irregular network of stout, irregular purple- 



