Volume VII. December, 1892. Number 3. 



JOURNAL 



OF 



MORPHOLOGY. 



A STUDY OF STENOSTOMA LEUCOPS O. SCHM.i 



HARVEY N. OTT. 



The following paper has been limited to the study of the 

 anatomy, and, as far as possible, the physiology, of a single form, 

 in the belief that in this line our knowledge of this difficult 

 group must, for the present, advance, and that extended com- 

 parisons of organs are still premature. 



Stenostoma leiicops has been selected as a simple and per- 

 haps central form, easily obtainable in abundance at all seasons 

 of the year. 



Of special papers on Stenostoma and on the family Micro- 

 stomidse there are known to me only those of Landsberg {2>']a and 

 'Z-jb), of Zacharias ('85), of Wagner ('89), and of Max Schultze ('49)- 

 Stenostoma leucops is abundant on plants in quiet water, such 

 as is found in small lakes and mill-ponds. It is more likely 

 to be found on chara than on other plants. The worm may be 

 easily obtained at any time during the summer and autumn 

 months by gathering a mass of these plants and allowing them 

 to stand in a glass vessel. The worms soon appear at the sur- 

 face of the water and on the sides of the vessel. My material 

 comes from a mill-pond of the Huron River, northwest of Ann 

 Arbor, and also from some small lakes three miles west of the 

 city. I experienced no trouble in keeping a supply of these 

 worms all winter in the covered glass vessels in the laboratory. 



1 Work from the Morphological Laboratory of the University of Michigan, under 

 the supervision of J. E. Reighard, was accepted as a thesis for the degree of Master 

 of Philosophy. ^ ^ 



