116 THE AMERICAN MONTHLY [April 



and ventrum plane ; the anterior half of ttie ventruni 

 traversed by a slight concavity which includes about one- 

 half the body width; flagelUi originating- together ue.'ir 

 the center of anterior border; the anterior flagellum 

 equals one body length and is directed obliquely forward 

 to the right side; ihe anterior third of this tlagellum is 

 vibratile and is fiexed still further to the right side ; the 

 posterior tlagellum equals nearly two body lengths; oval 

 aperture capacious, situated at the base of the anterior 

 tlagellum and conspicuous only when the infusorian is 

 engulphing or attempting to engulph large particles of 

 food; contractile vesicle large and very conspicuous, lo- 

 cated in the anterior body half near the sinistral border; 

 nucleus roundish and sub-central ; endoplasm blueish and 

 extrinsically granular; locomotion smooth and rapid 

 gliding. Size 1-1400 inch. Habitat — Pond water with 

 algae. 



This exceedingly active infusorian was found in a 

 number of different collections of water taken from a 

 pond in one of the parks in New Orleans. At no time 

 was this form observed until the water had become stale. 

 The oblique direction of the anterior tlagellum is not un- 

 like the same appendage of the genus Petalomonas. The 

 ventral concavity is well seen in a latero-ventral view, 

 which it often presents, as it has the habit of gliding 

 through and about debris heaps, after the manner of an 

 Aspidisca, but in a hurried and nervous sort of way. 

 The position and capaciousness of the oval aperture can 

 be verified only by observing the infusorian swallowing 

 or attempting to swallow large particles of food. It often 

 undertakes to swallow particles of food much larger than 

 itself. After it has taken any large particle of food it 

 immediately becomes much altered in shape — but after a 

 few contortions becomes itself again ; it is at this time 

 only that it demonstrates its flexibility. 



