PAPERS BY MEMBERS 89 



Quite varialDle irrespective of habitat. It usually pro- 

 duces zoospores in spring- and early summer, not in- 

 frequently also in the autumn. Specimens twenty 

 feet in length have been found in Whetstone creek. 

 \Miether these were single plants in the strict sense 

 could not be determined, but they had this appearance. 

 Attached to rocks in a rififle. the long fronds floated 

 down into an adjoining pool. Fide Collins. 



Cladophora fracta (Dillw.) Kuetzing. Fide Collins. 



Cladophora crispata (Roth) Kuetzing. 



I have not been able to separate these two species in tho 

 field. If they are distinct they present a hopeless tan- 

 gle for field study. They have been collected from 

 most of the ponds that are permanent or nearly so. 

 Fide Collins. 



Pithophora Varia A\'ille. 



Common in the permanent ponds. Produces akinetes at 

 all seasons and ages of the plants. Fide Collins. 



Siphonales. 

 Vaucheriaceae 



Vaucheria geminata lA'auch.) De Candolle. 

 Vaucheria germitata racemosa (A'auch.) A\'alz. 



Both the species and variety are abundant in the streams, 

 ponds, pools and on moist shaded ground throughout 

 eastern Illinois. Fide Collins. 

 Vaucheria hamata (\'auch.) De Candolle. 



A small form of this species was collected from Polecat 

 creek in the spring of 1^1 1. Fide Collins. 

 Vaucheria polysperma Hassall. 



Found in both the east and west Big Four ponds in the 

 autumn. 

 Vaucheria sessilis (A'auch.) De Candolle. 



\'ery abundant in all kinds of aquatic habitats. I have 

 " never found it growing on moist soil out of doors. 

 tlKUigh it grows commonly on soil in the greenhouse. 

 Vaucheria terreseris (A'auch.) De Candolle. 



Common on prairie pond margins and shaded soil. Even 

 in these situations it is less abundant than Vaucheria 

 geminata. 



Rhodophyceae 



Batrachospermum Boryanum Sirodot. 



Common in the town branch at the eastern edge of Char- 

 leston, and in Polecat creek south of Ashmore. I have 

 not seen anv fruiting material. Fide Collins. 



