THE EUGLENOIDINA OF OHIO 405 



striated longitudinally; paramylon cylindrical or rectangular, 

 numerous granules being present; movement free-swimming, ro- 

 tating on axis. Four species in fresh water from 16-120/x in length. 



TABLE OF SPECIES. 



A' Form attenuate, length more than 7 times the diameter. 



fii Form typically lunate; flagellum as long as body; 



length approximately 120/^ . . . . 1. M. falcatum 



B~ Form typically sigmoid; flagellum 1/2 as long as body; 



length of body 40-80m 2. M. tortuosum 



A2 Form not attenuate, length less than 6 times the diameter. 



Bi Narrowed into a neck like anterior end . . 3. M. pellucidum 

 B- Broadly rounded anteriorly . . . . 4. M. incurvum 



1. M. falcatum Zach. (Fig. 10, PI. XI). 



Comparatively narrow and decidedly curved into a form simi- 

 lar to a new moon, the posterior end pointed; periplast (?) ; flagel- 

 lum as long as body; nucleus (?) ; paramylon granules elongate. 



L. 120/.. D. 14/x. 



Distribution, Europe. Ditches. 



2. M. tortuosum (Stokes) (Fig. 11, PI. XXII). 



Typically in the form of a letter "S," gradually narrowed and 

 pointed posteriorly; periplast (?) ; flagellum 1/2 length of body; 

 nucleus central; paramylon granules elongate. 



L. 42-78/1. D. 5-13/x. 



Distribution, North America. Among decayed vegetation. 



The species was originally placed in the genus Atractonema 

 by Stokes who noted its soft flexible body which, however, was 

 persistent in shape. 



3. M. pellucidum Perty (Fig. 12, PI. XXII). 



Slightly curved, narrowed posteriorly with extremity rounded, 

 anteriorly developed into a neck-like process; periplast covered 

 with many weak striae ; flagellum slightly more than 1/0 length of 

 body; nucleus posterior; paramylon cylindrical, more or less 

 elongated. 



L. 39-40/x. D. 7-10/t. 



Distribution, Europe. Stagnant water. 



4. M. incurvum (Fres.) (Fig. 13, PI. XXII). 



Broadly cylindrical, slightly curved, broadly rounded on the 

 ends; periplast with comparatively distant striations ; flagellum 



