Lithodermeae. 197 



ANALYSIS OF THE GENERA. 



Sect. LITHODERMEAE. 



Sub-sect. DIDYMEAE. 



CHONDRIODERMA. Sporangia with a continuous porcelain- 

 like coat of lime. 



DlDYMlUM. Sporangia with a pulverulent, crystalline coat 

 of lime. 



LEPIDODERMA. Sporangia with isolated, large patches of 

 lime. 



SPUMARIA. Aethalium consisting of sporangia arranged in a 

 dendritic manner. 



DlACHAEA. Sporangia iridescent, without lime. 



Sub-sect. PHYSARAE. 



BADHAMIA. Threads of capillitium thick, containing lime 

 throughout their length. 



CRATERIUM. Sporangia with a well differentiated lid, or 

 splitting in a circumscissile manner. 



PHYSARUM. Capillitium with numerous large, irregular nodes 

 containing lime, and connected by thinner portions with- 

 out lime. 



TlLMADOCHE. Capillitium with small, scattered, elliptical 

 nodes containing lime internodes thin, elongated, with- 

 out lime. 



LEOCARPUS. Sporangia obovate, polished. 



OEINKQWSKIA. Capillitium with curved, free tips. 



Crateriachea. Columella present; threads of capillitium 

 mostly without nodes, containing lime. 



FULIGO. A cake-like aethalium. 



Sub-sect. DIDYMEAE. 



CHONDRIODERMA, Rost. (in part). 



Sporangium stipitate or sessile, wall single or double, outer 

 wall charged with lime, perfectly smooth, porcelain-like, dehis- 



