66 DAVENPORT ACADEMY OF SCIENCES. 



found in the waters of this state which has been tentatively referred 

 to this species. Body elongate-oval, about two and one-half times 

 as long as broad, highly elastic. Anterior extremity continued as 

 a short, neck-like extension. Oral aperture terminating a cone- 

 like projection which is smaller than the neck and slightly con- 

 stricted from it. The anterior extremity of the neck bearing a 

 circle of cilia larger than those of the general surface. 



Endoplasm completely filled with dark globular masses, render- 

 ing the body opaque and concealing the nucleus. Contractile 

 vesicle posterior. 



L,ength of body, 90 microns. 



Lacryniaria cohnii is reported to be a salt-water form but the 

 species occurring in this state is so closely allied to it that I would, 

 at least for the time being, classify it here. The species has been 

 found in Lake Okoboji and also in some of the eastern counties of 

 this state. Its habitat is fresh water among aquatic plants. 

 Movement is accompanied by rapid revolution on its longitudinal 

 axis. 



lyACRYMARIA TRUNCATA StokeS. 



Body elongate, somewhat flask-shaped, flattened. Rounded 

 posteriorly, produced anteriorly into a long neck-like region, the 

 anterior border of which is obliquely truncated and slightly 

 dilated. Surface longitudinally striate. Cilia of the anterior ex.- 

 tremity slightly larger than those of the general surface. Oral 

 aperture in the anterior truncated border. Nucleus long, band- 

 like, twisted and convoluted in the posterior region. Contractile 

 vesicle posterior. 



Length, 160 microns. (Fig. loi, PI. XIII.) 



This species may be found in long-standing infusions of pond 

 water, the truncated anterior border and greatly convoluted 

 nucleus serving to readily distinguish it. The organism is a rapid 

 swimmer, rotating on its longitudinal axis. 



Lacrymaria oeor Miill. 



Body elongate-ovate, posterior extremity pointed. Anterior 

 extensile neck capable of being extended many times the length 

 of the body. Surface obliquely striate in two directions. Nucleus 

 double, central. Contractile vesicles more than one. 



