146 THE NORTH AMERICAN SLIME-MOULDS 



Fructification in the form of flat, pulvinate plasmodiocarps, or, 

 anon, sporangiate, the sporangia sessile, sub-globose, ellipsoidal, elon- 

 gate, irregular, confluent, yellowish-grey, the peridium covered more 

 or less completely with dull white, crystals or crystal-like scales; 

 columella, where visible, yellowish-brown, calcareous; capillitium, 

 coarse, rigid, more or less branched and united, or colorless, delicate, 

 forming a definite net; spores distinctly warted, purple 10-12 /x. 



This is a most remarkable species. The sporangiate forms little 

 resemble those distinctly plasmodiocarpal. In the former the calcic 

 scales and crystals are distinct and quite as in L. tigrinum; in the 

 latter they are cuboid, irregular. The wall of the peridium in the 

 plasmodiocarps at hand is black, and the covering accordingly shows 

 white ; in the sporangial forms the wall is brown, and the scales have 

 a yellow tinge as if tinged with iron. In the sporangial presentation 

 the capillitium is intricate delicate; in the plasmodiocarp, rigid, dark- 

 colored, etc. This looks like a didymium and in so far justifies the 

 opinion of earlier students. Fries, of course, includes all these things 

 with the didymiums, and D. squamulosum probably often sheltered 

 them under extended wing. 



Didymium granuliferum Phill., Grev., V., p. 114, from Cali- 

 fornia is by European authors referred here. The capillitium carries 

 calcareous crystalline deposits in special vesicles and the spores show 

 remarkable variation in unusual size — 15—30 ju.^ 



Should probably be entered Lepidoderma granuliferum (Phill.) 

 Fr., spores 15-18 fi. 



Utah, — Harkness. 



3. Lepidoderma chailletii Rost. 



Plate XVIII., Figs. 6, 6 a, 6 b. 



Sporangia distinct, coalescent or plasmodiocarpous, large, when iso- 

 lated 1-1.5 mm., dull drab in color, very sparsely sprinkled with 

 white tetrahedral or irregular scales; the peridium thin, more or less 

 translucent, rugulose, dull brown, persistent ; columella none ; capil- 

 litium abundant, under the lens purple-brown, sparingly branched, 



1 Doubtless immature ; v. Mitteil, Natur<vjiss. GeseU. Wintert., VI., p. 64, 

 Lister quoted by Schinz. 



