120 The Ohio Journal of Science [Vol. XXI, No. 4, 



Chlorella pachyderma Printz. 



Previously reported from Asia. 



Kirchneriella obesa (W. West) Schmidle var. major (Bernard), G. M. 

 Smith. 



Although but a few specimens of this alga were noted, it is 

 without doubt the variety figured by Smith. ^ 



Scenedesmus acuminatus (Lemm.) Chodat. 



Very common in the digestive tract of the gizzard shad. 

 The dimensions of the cells, the distance between the apices, 

 and the general shape of the coenobium unquestionably place 

 it with the typical form. 



In the identification of the species of Scenedesmus, the 

 classification of G. M. Smith^ has been followed throughout. 



Coelastrum morus W. & G. S. West, var. capense Fritsch. 



Previously described from Africa. The American material 

 has cells 10-15 microns in diameter; the emarginate- truncate 

 warts 1-3 microns. Otherwise like the description given by 

 Fritsch. 2 



Pediastrum clathratum (vSchroeter) Lemm. 



In an examination of thousands of specimens of Pediastrum 

 with single spines, the constancy of small intercellular spaces 

 between the cells seems sufficient for the retention of this alga 

 as a distinct species. I have listed four varieties of this species 

 in Table III, based on the nature of the intercellular spaces. 



It was possible to find practically all graduations between 

 P. simplex and P. Sturmii Reinsch. This would seem to 

 bear out the statement of Harper-* that the Sturmii forms are 

 "merely colonies of P. simplex approaching the reproductive 

 stage." Similar gradations were also noted between P. clath- 

 ratum and P. ovatum (Ehr.) A. Br. 



Ulothrix oscillarina Kuetz. 



Only a few short filaments of this alga were found, but 

 the dimensions of the cells and shape of the chloroplasts agree 

 so closely with the description given by Fritsch- that there 

 seems little doubt for referring the material to this species. 



Spirogyra Weberi Kuetz. 



No fruiting material was found in the gizzard shad. But 

 the presence of fruiting cells in material collected at Buckeye 



