344 OHIO BIOLOGICAL SURVEY 



the manuscript of the present paper, were closely in agreement 

 with those of the "Siisswasserflora," making due allowance for 

 individual viewpoints, there are several distinctions in the treat- 

 ment of the material which may be mentioned. The synoptic 

 tables for the separation of species, etc., are not dichotomous as 

 are the tables in the following pages where only two possibilities 

 "A'" and "A-," etc., are presented at a time. With the assump- 

 tion that the characters utilized are of equal value, dichotomous 

 tables certainly furnish a better means toward the classification 

 of organisms than tables where three, four or more similar char- 

 acters are relatively considered at the same time. The present 

 paper furthermore aims to note all recognized species and varieties 

 of the order distributed throughout the world, including the few 

 forms which are marine. The paper of Lemmermann approaches 

 completeness in this respect, inasmuch as the group is a cosmo- 

 politan one, in that almost any restricted area where the organ- 

 isms are carefully studied will furnish representatives of nearly 

 all known species. He omits the marine forms, however. 



The Euglenoidina are of microscopic size, rarely exceeding 

 200ix^ — usually 10-60^ — in length and are in general inhabitants 

 of the fresh water, although a few are marine and a few parasitic. 

 In common with most other minute organisms which are aquatic, 

 they are uniformly distributed throughout the temperate and trop- 

 ical regions of the world. Consequently in a review of the species 

 found in Ohio it has seemed advisable to also include all described 

 forms, inasmuch as a majority of these will eventually be found to 

 occur in the state. 



The work hitherto done in connection with the Euglenoidina 

 found in Ohio is comprised in two check lists of Protozoa. The 

 first, a "Report on the Protozoa of Lake Erie," by Jennings (U. 

 S. Fish Com. Bull. 1889), who notes fifteen species of the order 

 from localities near Put-in-Bay. The second, a list of "The Pro- 

 tozoa of Sandusky Bay and Vicinity," by Landacre (Proc. Ohio 

 Acad, of Science, Vol. 4, Pt. 10, 1908), lists thirty species with 

 many interesting notes. Fifty-two species from Ohio are given in 

 the present paper, which also includes one hundred and ninety-four 

 species which have been described from various parts of the world. 

 No tables or figures are presented in either of the preceding lists. 



1 One micron (ly) equals one thousandth of a millimeter. 



