ii8 Natural History Bulletin. 



the base of the fruiting plasmodium on all sides. Sporangia 

 erect, prismatic, hexahedral. yEthalium, olive or lead-colored, 

 roughened by the arched apices of the numerous peridia. 

 Spores ochre or ochre-brown, dehcately warted, .007-.012. 



An elegant and most pecuhar species; perfectly finished, 

 firm, constant and happily not rare. The hundreds of tiny 

 sporangia packed so closely together might deceive the inex- 

 perienced collector and be mistaken for the fruit of Trichia 

 chryrospenna, but the first glimpse of the dainty architecture 

 which the lens reveals is sufficient for immediate recognition. 

 Habitat; moist stumps and twigs in the denser woods. 



IV. CRIBRARIACEiE. 



Sporangia, single, isolated and generally stalked. Peridia 

 with net-like thickenings which persist, the unthickened por- 

 tions disappeanng at maturity. 



«KEY TO THE GENERA. 



Thickening of the peridium scalariform from base of the sporocyst 



to apex, Dyctidium. 



Thickenings reticulate, lace-like, Cribraria. 



DICTYDIUM, Schrader. 



Sporangia, separate, stalked, about two millimeters high 

 and half a millimeter wide. The radiate veins of the peridia 

 parallel and equal, meridional, connected by very delicate 

 transverse threads forming rectangular meshes. At maturity 

 the walls of the peridium except where thickened vanish, leav- 

 ing a basket-like structure filled with spores. 



7. DiCTYDIUM CERNUUM, PcrSOOH. 



Sporangia numerous, small, rather long-stalked, nodding, 

 at first almost black, violet, then purple-brown; the spore- 

 case oblate or more or less depressed above, especially when 

 mature. Spores brown, smooth, .004-005. July — August. 



