136 Cincinnati Society of Natural History. 



Order II.— RETICULARIACE.€. 



Sporangia simple, regular and stipitate, or com- 

 pound, forming an sethalium ; the wall a thin mem- 

 brane with distinct fibrous thickenings upon the 

 inner surface, the membrane, or at least certain 

 portions of it, disappearing usually at the maturity 

 of the spores, leaving behind the more permanent 

 fibrous thickenings as a more or less definite capilli- 

 tium. Spores globose, purple, brown, ochraceous, 

 rarely violaceous. 



In this order the threads of a capillitium first make their 

 appearance ; but they are confined to the inner surface of the 

 wall of the sporangium, being set at liberty by the early decay 

 of the outer membrane. 



Table of Genera ok Reticulariace/E. 

 a. ^Et/ialia. 



1. Reticularia. .'Ethalium composed of numerous slen- 

 der sinuous sporangia which repeatedly branch and anasto- 

 mose. 



2. Clathroi'Tvciiium. ^Ethalium composed of numerous 

 regular erect sporangia. 



Ik Sporani^ia simple. 



3. Cribraria. Capillitium of slender threads combined 

 into a network of polygonal meshes. 



4. DiCTVDiUM. Capillitium of numerous con\ergent ribs, 

 which extend from base to apex, and are united by fine trans- 

 verse fibers, thus forming a network of rectangular meshes. 



I. RliTlCULARIA, Hull. .Uthalium composed of numer- 

 ous slender sinuous sporangia, which repeatedly branch and 

 anastomose, closely packed together and seated upon a com- 



