PAPERS BY MEMBERS 77 



has been found in fruit rarely. Fruits in late spring and 

 summer. Fide Collins. 

 Spirogyra nitida ( Dilhv.) Link. 



Common in ponds throughout eastern Illinois. Fruits in 

 summer and autumn. The dimensions are often smaller 

 than those given by Collins. Cur form corresponds 

 closely to the description given by Hassall in his Bri- 

 tish Freshwater Algae. 

 Spirogyra orthospira Xaegeli. (Spirogyra Majuscula Kuetz.) 

 Bottom laud ponds and wet-weather pools. Common. 

 Fruits from April to July. Fertile cells not infre- 

 quently inflated. Fide Collins. 

 Spirogyra Petitiana mss. 



A species near decimina. Occurs only in the new Tile 

 Factory pond. Charleston, but has been found for six 

 years during the summer. 

 Spirogyra porticalis (Mueller) Cleve. 



\'ery common in ponds, small and large streams. Beyond 

 Charleston I have collected it at Lawrenceville. Olnev 

 and Paris. Fruits from March to May. Fide Collins. 

 Spirogyra punctiformis mss. 



Found only in the Tile Factory ponds. Charleston. Near 

 punctata. Differs in having one or two chromato- 

 phores. and larger dimensions. 

 Spirogyra quadrata ( Hass.) Petit. 



Collected in the new Tile Factory pond. Charleston. 

 Spirogyra setiformis (Roth) Kuetzing. 



Common in ponds at Charleston and Ashmore. Fruits 

 usually in late autumn. Spore wall hyaline showing 

 the chromatophores within. Fide Collins . 

 Spirogyra Spreeiana Rabenhorst. 



Rare in ponds near Charleston and Ashmore. Fruits dur- 

 ing April and May. ^ 

 Spirogyra stictica ( Eng. Bot.) Wille. 



Rather common. Has been collected in a fruiting con- 

 dition at Ashmore. Sullivan and Casey. Fruits dur- 

 ing April and !May. 

 Spirogyra submaxima mss. 



Has been collected annually in a pond east of Charleston. 

 Near maxima, but has eight or nine chromatophores, 

 spores smooth and with smaller dimensions. 

 Spirogyra tenuissima (Hass.) Kuetzing. 



\'ery common throughout eastern Illinois, in ponds, 

 pools and intermittent streams. Fruits in early spring. 

 Spirogyra tenuissima rugosa mss. 



Rather frequent with the type. Medium spore wall 

 minutely roughened. 



