Lepidoderma 135 



more often with a dense, thick, spongy, crust of crystalline lime. 

 The variety seems to connect the genera Mucilago and Fuligo 

 through F. intermedia, as lime in the form of crystalline nodules is 

 found occasionally in species of Fuligo. Similar variations from 

 nearly free sporangia to compact aethalia are also found in Tubi- 

 fera ferruginosa. Var. dictyospora R. E. Fries (Arkiv. Bot. 1: 66. 

 1903) with reticulate spores has not been reported from North 

 America. 



Genus 13. LEPIDODERMA de Bary; Rost. Versuch 13. 

 1873. 



Sporangia stalked, sessile, or forming plasmodiocarps; sporan- 

 gial wall cartilaginous, more or less clothed with apparently super- 

 ficial crystalline discs or scales, the scales enclosed in pockets or 

 vesicles of the sporangial wall, but easily dislodged; capillitium 

 rigid and without lime, except in L. Carestianum var. granuliferum. 



Type species: Didymium tigrinum Schrad. 



Sporangia with orange stalks and walls. 1. L. tigrinum 

 Sporangia forming plasmodiocarps with brownish or pur- 

 plish walls. 2. L. Carestianum 

 Sporangia usually sessile, with pale yellow walls. 3. L. Chailletii 



1. Lepidoderma tigrinum (Schrad.) Rost. Versuch 13. 1873. 

 Didymium tigrinum Schrad. Nov. Gen. PI. 22. 1797. 



Plasmodium orange-yellow (Lister). Sporangia scattered, 

 subglobose, flattened and umbilicate beneath, stalked, rarely 

 sessile. 0.8 to 1.5 mm. diam., olive or purplish gray, glossy, 

 more or less covered with flat, rounded, angular, or star-shaped 

 crystalline scales of lime; sporangial wall cartilaginous, of two 

 closely combined layers, orange-yellow. Stalk stout, cylindrical, 

 0.5 to 1.2 mm. high, furrowed, orange or orange-brown, of a 

 spongy texture within, containing deposits of lime, rising from a 

 yellowish or orange hypothallus. Columella large, hemispherical, 

 orange, of the same texture as the stalk, containing deposits of 

 lime in rounded granules. Capillitium profuse, of straight or 

 flexuose threads, sparingly branched, dark purplish brown or 

 gray. Spores dark purplish gray, minutely spinulose, 10-13 ju 

 diam. (Plate 10, fig. 4.) 



Type locality: Europe. 



