BULLETIN 



OF THE 



Illinois Qtate I aboratory 



OF 



NATURAL HISTORY, 



Urbana, Illinois. 



VOLUME V 



ARTICLE V.— PLANKTON STUDIES. II. ON PLEODORINA 

 ILLINOISENSIS, A NEW SPECIES FROM THE PLANK'- 

 TON OF THE IILINOIS RIVER. 



By C. A. KOFOID, Ph. D. 



Illinois State Laboratory of Natural History, 



URBANA, ILLINOIS. 



September, 1898. 



