﻿168 



Cincinnati Society of Natural History. 



dirty green scum becomes one of our most interesting plants. The small 

 basin, strange to say, yielded also desmids of the genera Closterium and 

 Cosmarium, making a most remarkable flora for a bod)- of water not over 

 two and a half feet in diameter. 



We now come to the plant that grew so profusely in the large basin 

 and first drew my attention to the new collecting field. This was the 

 Stigeocloniiim ionic, Ag. It was found fringing the whole outer wall of the 

 basin, in some places extending over two indies into the water. On the 

 base of the fountain was another mass of what I supposed to be the 

 same although I could not get at it to make a closer examination. 



Under the microscope the slimy green substance collected becomes a 

 mass of beautiful branching filaments, made up of many ( ells. Each cell 

 contains chlorophyl, in vegetating filaments arranged in an irregular stel- 

 late mass not quite reaching the ends of the cells. In younger specimens 

 this is not so apparent, while in filaments forming spores the entire cell is 

 filled. I was fortunate enough to see this fruiting. The spores were 

 formed in main filaments frequently between branches that had far out- 

 grown the parent, which probably stopped growing when the formation- 

 commenced. The filaments would become constricted at the cell walls 

 and the contents of each cell would form a single zoospore which eventu- 

 ally broke away, leaving the empty cell very delicate and very hard to 

 see. In one collection that I made these spores were forming so rapidly 

 that every dip would bring up hundreds of them. We have, in all, some 

 six or eight species of Stigeoclomum, very hard to distinguish, however. I 

 have found but one other in our waters, that in a ditch in Sedamsville. 



THE MYCOLOGIC FLORA OF THE ME4MJ VALLEY, 



OHIO. 



By A. P. Morgan. 

 [Continued from Vol. VIII, p. no.] 

 Genus II. Polyporus, Fr. (Continued). 



V. RESUP1NATI. 



Pileus none, the fungus therefore absolutely resupinate ; the pores 

 placed immediately upon the wood or the mycelium, seldom with an in- 

 terposed subiculum. 



