The Myxo)nycetes of the Miajni Valley, Ohio. 155 



layer of the wall snow-white, thin, smooth, distinct from the 

 inner membrane, breaking into pieces and falling away ; the 

 inner membrane thin, opaque and bluish or pellucid and 

 iridescent. Columella reduced to a^ thin layer of scales and 

 granules upon the brownish basal membrane. Capillitium 

 scanty, consisting of short nearly colorless threads, which are 

 simple, or fork a time or two. Spores globose, even, dark 

 violaceous, 10-13 niic. in diameter. 



Growing on bark, leaves, twigs, herbaceous stems, etc. 

 Plasmodiocarp .3-. 5 mm. in thickness and variable in length, 

 sometimes elongated several millimeters. 



11. DiDERMA RETicuLATUM, Ro.st. Plasmodiocarp very 

 much depressed, roundish, oblong, much elongated and flex- 

 uous, closel}' crowded together and confluent ; the hypoth- 

 allus a thin white granulose layer of lime, scarcely broader 

 than the plasmodiocarp. The outer calcareous layer of the 

 wall white, distinct, very fragile and easily shelling off; the 

 inner membrane much shrunken and withdrawn from the 

 outer coat, rugulose, cinereous, with a dense closely-adherent 

 layer of granules of lime. The columella a thin alutaceous, 

 granulose-roughened layer, extending along the base of the 

 plasmodiocarp. Capillitium of threads short and very slender, 

 colorless, somewhat branched. Spores globose, even, pale 

 violaceous, 6-8 mic. in diameter. Plate XII, Fig. 47. 



Growing on old wood, leaves, twigs, etc. Plasmodiocarp 

 .5-. 8 mm. in width, much flattened and usually closely 

 crowded. The rough calcareous base of the plasmodiocarp 

 might be considered as either all columella or all hypothallus, 

 with the upper surface leather-colored. I am indebted to 

 Arthur Lister, of London, for the determination of my speci- 

 mens. 



12. DiDERMA EFFUvSUM, Schw. Plasmodiocarp very much 

 flattened, longitudinally creeping and reticulate or altogether 

 widely eff"used ; hypothallus none. The wall very thin, 

 smooth, white or cinereous, the thin membrane covered by a 

 single layer of closely-adherent granules of lime, rupturing 

 irregularly. The columella reduced to a thin alutaceous layer 

 of granules of lime, forming the base of the plasmodiocarp. 

 Capillitium of short colorless threads, extending from base to 



