LEE BARKER WALTON 29 



ent on microscopic forms, among which the Naids occupy 

 an important position, it is evident that the distribution 

 of such microscopic organisms controls to a large extent 

 the fish supply in any given locality. 



The somewhat unique location of Cedar Point with the 

 open lake on the north and a portion of Sandusky Bay 

 extremely rich in aquatic vegetation on the south, renders 

 the Lake Laboratory situated there a station particularly 

 well adapted to the study of the animal and plant life 

 occurring in fresh water and to the investigation of the 

 various problems of biological importance connected 

 therewith. 



The present study was carried on at the laboratory 

 during a period of six weeks in July and August, 1905, 

 the greater portion of the time, however, being occupied 

 with other work. Consequently the record of species is 

 undoubtedly far from complete, although 10 species, 7 of 

 them new to science, are noted. The large proportion 

 of new forms indicates the present condition in regard to 

 the systematic study of the Naids in the United States, 

 and while the writer has no wish to be classed as a "species 

 maker," nevertheless it is important to lay the foundations 

 for future biological studies by first considering those 

 groups containing individuals resembling each other suf- 

 ficiently well to be called "species." 



The principal papers dealing with American Naids out- 

 side of the excellent monographs of Michaelsen (:00) and 

 Beddard ('95), are those of Leidy ('50a, '50b, '52a, '52b, 

 '80), Minor ('63), Reighard ('85), Cragin ('87), and 

 Smith ('96 and :00). In addition to these, papers in- 

 dispensable to the student of the group have been pub- 

 lished by Beddard, Benham, Bourne, Bousfield, Bretschner, 

 Michaelsen, Tauber, and Vejdovsky, that of the last 

 author being classical in its morphological treatment of 

 the forms. The majority of these papers are either in the 

 library of the writer, or in the library of the department 

 of biology of Kenyon College. Mention should here be 

 made of the courtesies extended by the American Museum 

 of Natural History, New York, the library of Cornell 

 University, and the Museum of Comparative Zoology of 



