INTRODUCTION 3 



from which algal species are reported, over 40 lie along the Missis- 

 sippi, Ohio, Wabash, Illinois, Sangamon and Rock Rivers. With 

 but few exceptions, these counties, for the most part represented by 

 small numbers of species, have not been studied at all in the interior 

 portions, but the records are based on collections from the streams 

 along which these counties lie. The principal exceptions are Clark, 

 Lawrence and Pulaski Counties, and a few others the inland waters 

 of which have been studied to a minor extent. The only State area 

 that has been intensively studied algologically over any considerable 

 number of years is east-central Illinois in the region centering about 

 Coles County, where Dr. E, N. Transeau did his especially note- 

 worthy work early in this century. Although Cook County shows a 

 greater total, 502 species, than any other county, it should be noted 

 that the figure is weighted considerably by the large number of Lake 

 Michigan species, mainly diatoms, which are included. Coles County 

 to date is the most critically and intensively studied interior area 

 of the entire State, with a total representation in this catalog of 413 

 species and varieties of algae. 



The catalog contains a total of 178 genera and 962 species, varieties 

 and forms of algae distributed among the various algal groups as 

 summarized in the following classified list. The first number in each 

 case refers to genera and the second to species, varieties or forms. 



Cyanophyta 29-98 

 Myxophyceae 29-98 

 Chroococcales 8-16 



Chroococcaceae 8-16 

 Chamaesiphonales 1-1 

 Pleurocapsaceae 1-1 

 Hormogonales 20-81 

 Homocystineae 7-46 



Oscillatoriaceae 7-46 

 Heterocystineae 13-35 

 Nostocaceae 5-22 

 Scytonemataceae 3-6 

 Stigonemataceae 1-1 

 Rivulariaceae 4-6 

 Rhodophyta 2-2 

 Rhodophyceae 2-2 

 Nemalionales 2-2 



Batrachospermaceae 1-1 

 Thoreaceae 1-1 

 Chrysophyta 51-308 

 Xanthophyceae 4-14 

 Heterococcales 2-8 



Botryococcaceae 1-2 

 Ophiocytiaceae 1-6 

 Heterotrichales 1-4 



Tribonemataceae 1-4 

 Heterosiphonales 1-2 

 Botrydiaceae 1-2 

 Chrysophyceae 6-15 

 Chrysomonadales 5-14 

 Chromulineae 2-4 



Mallomonadaceae 2-4 

 Isochrysidineae 2-2 

 Syncryptaceae 1-1 

 Synuraceae 1-1 

 Ochromonadineae 1-8 

 Ochromonadaceae 1-8 

 Rhizochrysidales 1-1 



Rhizochrysidaceae 1-1 

 Bacillariophyceae 41-279 

 Centrales 6-30 



Coscinodiscineae 5-28 

 Coscinodiscaceae 4-27 

 Eupodiscaceae 1-1 



