IOWA ACADEMY OF SCIENCE 
73 
Septa between the cells folded back, replicate. 
Membrane of Zygospore smooth. 
One (rarely two) spirals in a cell. 
Vegetative cells 8-12 u in diameter S. tenuissima 
Vegetative cells 13-18 u in diameter S. inflata 
Vegetative cells 11 u or more in diameter. 
Diameter Zygospores 26-30 u £>. weberi 
Diameter Zygospores 30-33 u S. laxa 
Diameter Zygospores 20-33 u S. grevilleana 
Diameter Zygospores 40-48 u S. quadrata 
Three spirals in a cell S. insignis 
Membrane of the Zygospore areolate or punctate S. calospora 
106. S. porticalis Cleve. (S. quinina). 
Iowa City. Hobby. 
Ames. Bessey. 
Eagle Grove. Hewitt’s Pond. Buchanan. 
107. 
S. porticalis var. alpina Kuetz. 
Iowa City. Hobby. 
108. 
S. longata Kuetz. 
Iowa City. Hobby. 
Ames. Bessey. 
Eagle Grove. Pond. Buchanan. 
109. 
S', varians Kuetz. 
Iowa City. Hobby. 
110. 
S. communis Kuetz. 
Iowa City. Hobby. 
111. 
Sf. decimina Kuetz. 
Iowa City. Hobby. 
Eagle Grove. Pond. Buchanan. 
112. 
S. rivularis Rabenh. 
Iowa City. Hobby. 
113. 
S. nitida Link. 
Iowa City. Hobby. 
Eagle Grove. 
In pond among lily pads. Buchanan. 
1U. 
S. jugalis Kuetz. 
Eagle Grove. 
Floating in Hewitt’s Pond. Buchanan. 
115. 
S. setiformis Kuetz. 
Eagle Grove. Jenning’s Pond. Buchanan. 
116. 
S. majuscula Kuetz. 
Iowa City. Hobby. 
Ames. Bessey. 
117. 
S. 
Eagle Grove. Hewitt’s Pond. 
maxima Wittr. 
Buchanan. 
118. 
S. 
Eagle Grove. Jenning’s Pond. 
crassa Kuetz. 
Buchanan. 
119. 
S. 
Iowa City. Hobby. 
intermedia Rabenh. 
120. 
S. 
Iowa City. Hobby. 
adnata Kuetz. 
Iowa City. Hobby. 
