164 Cincinnati Society of Natural History. 



16. Hemiarcyria. Spiral ridges of the capillitium paral- 

 lel and conspicuous. 



17. Calonema. The surface of the tubules traversed by 

 a system of branching veins. 



b. Capillitium of short, slender tubules, called elaters y which 

 are wholly free. 



18. Trichia. Spiral ridges of the capillitium parallel and 

 conspicuous. 



19. Oligonema. Capillitium scanty, composed of elaters, 

 habitually irregular and abnormal. 



§3. COLUMELUFEELE. 



Sporangium containing no lime ; stipe entering the spo- 

 rangium and forming a more or less elongated central col- 

 umella, which gives origin to a capillitum of rigid, persistent 

 brown threads. 



VII. STEMONITACE^E. Sporangia, globose or ovoid to 

 oblong and cylindrical, stipitate; the wall very thin and frag- 

 ile, soon disappearing. 



A. stipe and cohimella brown or black. 



a. The cohimella scarcely reaching the center of the sporan- 

 gium. 



20. CIvAstoderma. Threads of the capillitium forking 

 repeatedly, but not combined into a network. 



21. Lamproderma. Threads of the capillitium branch- 

 ing and anastomosing to form a network. 



b. The columella extending beyond the center of the sporan- 

 gium. 



22. Comatricha. Threads of the capillitium forming 

 only an interior network, attaining the wall by numerous 

 more or less elongated free extremities. 



18 



