DIANEMA 1 79 



ORDER V. 

 TRICHIACE^:. 



Fructification sporangial, rarely plasmodiocarpous, the sporan- 

 gia stalked or sessile, gregarious or closely crowded, limeless 

 throughout ; the capillitium of definite threads, free or attached 

 to the sporangial wall, isolated or combined into a net ; spores 

 generally some shade of yellow, never purple or black. 



The distinguishing feature in this order is found in the 

 peculiar sculpture of the capillitial threads. This is suggested 

 by the tubules of Lycogala, though probably the resemblance 

 is superficial only. The individual threads, as in Trichia, are 

 called elaters, from their probable efficiency in spore dispersal. 



As here limited, the order is coextensive with the Calonemece 

 of Rostafinski, except that it includes in addition the genera 

 Prototrichia and Dianema. The course of differentiation may 

 be assumed to start with Dianema, through the Perichcenece to 

 the Arcyrice, and again from the same starting-point through 

 Prototrichia to the Trie hies. 



Key to the Families of the Trichiaceae. 



A. Capillitial threads transverse to the sporangial cavity, attached usually 



at each end, plain or only slightly roughened . . DIANEME^; 



B. Capillitium plain, papillose, or spinulose, often scanty, not netted, the 



threads sometimes attached by one end to the sporangium wall, 



PERICH/ENE.E 



C. Capillitium a distinct net, usually attached below to the sporangial 



wall ; sculpture various, not of continuous spiral bands, ARCYRIE^E 



D. Capillitial threads transverse, fascicled, attached at both ends, but 



sculptured by well-defined spiral bands . . PROTOTRICHIE.E 



E. Capillitial threads typically free, sometimes more or less branched, 



forming a loose net attached below, characterized by definite spiral 

 bands, or sometimes by scattered rings . . . TRICKIER 



