RETICULARIA 239 



and with many delicate, free, pointed ends. Spores pale yellow, usu- 

 ally united in twos or threes, and ovoid or flattened on one side, when 

 free, globose, very minutely spinulose, 9.5-10.5 jjl. 

 Colorado (Sturgis). 



5. Enteridium yabeanum Emoto 



Bot. Mag. Tokyo 46 : 170. 1932. 



iEthalium thin, expanded, irregular, 2-23 cm. in extent, 3-8 mm. 

 thick; bister* or natal-brown*, covered by a thin brownish membrane 

 and borne on a well-developed brown hypothallus; pseudocapillitium 

 of brown, perforated plates; spores separate, olivaceous in mass, 

 colorless under the lens, uniformly warted, 6-7.5 /x. Plasmodium slate 

 black. 



Distinguished by its large size from all other species, from E. roze- 

 anum by the spore characters, the thin fructification and the oliva- 

 ceous coloring, from E. olivaceum by the large size and the smaller, 

 unclustered spores. 



Japan. 



2. Reticularia Bull, emend. Rost. 

 Versuch6. 1873. 

 1791. Reticularia Bull, Champ. 83, in part. 



Fructification sethalioid, the pseudocapillitium consisting of mem- 

 branous plates, branching and anastomosing in various ways, and 

 generally giving rise at the sides and especially above to long, slender, 

 flexuous threads, the whole forming a spongy mass; outer cortex silvery 

 white, becoming copper colored; hypothallus well developed, white; 

 spore-mass and threads umber or rusty brown. 



It has been customary to speak of the frayed and perforated plates 

 of the pseudocapillitium as degenerate sporangial walls. Wilson and 

 Cadman, in their beautiful and detailed study of the single species 

 included in this genus, demonstrate that this view is untenable. These 

 authors regard the entire fructification as a single sporangium, but 

 surely a sporangium formed from a dense aggregation of protoplasm 

 representing many plasmodial strands is not completely homologous 

 with what is called a sporangium in a trichia or a physarum. It may, 

 on the other hand, easily be correlated with the fructification in Fuligo 

 or Lycogala, and would seem to represent a true aethalium as opposed 

 to the pseudo-aethalia formed by the obvious coalescence of more 

 or less clearly distinguishable sporangial units. 



A single species: 



