Nov., 1915] Notes on the Zygnemales 31 



Vegetative cells 56-66yu x 120-335^, end walls plane; 4-5 

 chromatophores, nearly straight or making a half turn; conju- 

 gating cells geniculate, shortened; fertile cells inflated up to 

 135ju; conjugating tube very short and broad; zygospores 

 ellipsoid, 75-105ju x 95-135/x median wall smooth, yellow. Type 

 in U. S. National Herbarium, collected by J. D. Smith, in S. W. 

 Florida, March, 1878. 



In its dimensions 5. floridana is intermediate between 5. 

 stictica (Eng. Bot.) Wille and S. ceylanica Wittrock. In several 

 publications the statement is made that S. ceylanica is inter- 

 mediate between S. stictica and the common forms of Spirogyra. 

 A study of authentic material of this species has shown that it 

 has not intermediate characters, but with its spores having a 

 minutely pitted median wall, it seems to be intermediate 

 between S. floridana and S. illinoiensis Transeau, the most 

 specialized form in the Sirogonium group of the genus. 



Throughout the study of these collections the writer has 

 been greatly assisted by Mr. Hanford Tiffany, now a teacher in 

 the Charleston, Illinois, High School. It is a pleasure to 

 acknowledge my indebtedness to the many collectors who have 

 sent me specimens for study. 



