LEPIDODERMA 145 



Key to Speciea of Lepidoderma 



A. Sporangia stipitate, stipe brown \. L. t'tgrinum 



B. Sporangia sessile, plasmodiocarpous, spores 10-12 M 2. L. carestianum 



C. Sporangia plasmodiocarpous, spores 8-10 /* . . . 2. L. chailletii 



1. Lepidoderma tigrinum (Schrad.) Rost. 



Plate XIV., Fig. 7. 



1797. Didymium tigrinum Schrad., Nov. Gen. Plantarum, p. 22. 

 1873. Lepidoderma tigrinum (Schrad.) Rest., Versuch, p. 13. 



Sporangia scattered, rather large, hemispherical-depressed, stipitate, 

 umbilicate beneath, the peridium shining, olivaceous or purplish, 

 tough, covered more or less abundantly with angular scales ; the stipe 

 stout, furrowed, dark brown, but containing 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 branching threads radiating from the columella ; 

 spores dull purplish-brown, minutely roughened, 10—12 /x. 



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 Didymium. The 

 species occurs in hilly or mountainous regions, on moss-covered logs. 

 The Plasmodium pale yellow, some part of it not infrequently re- 

 mains as a venulose hypothallus connecting such sporangia as are near 

 together. 



New England to Washington and Oregon ; Vancouver Island. 



2. Lepidoderma carestianum {Rabenh.) Rost. 



1862. Reticularia carestiana Rabenh., MS. Fung. Eur. exsic, No. 436. 

 1875. Lepidoderma carestianum (Rabenh.) Rost., Mon., p. 188. 

 1891. Amaurochaete minor Sacc. & Ell., Mich., II., p. 566. 



at least, of calcium carbonate. We may also discover that in the case before 

 us the crystal or scale lies indeed enclosed in a filmy sac of organic origin, and 

 that could we have seen the outer peridium as it came to form, we might prob- 

 ably have found it made up largely of an ectosarcous foam in whose cavities 

 the excreted calcium found place for tabulate crystallization. In other species 

 listed, conditions are different, and the crystals assume a different shape. The 

 phrase "bicarbonate of lime" quoted in this connection in the former edition 

 of this work from Mr. Massee's Monograph, etc., is not clear. 



11 



