96 Lake Maxinkiickee, Physical and Biological Survey 



1. ARCELLA VULGARIS Ehrenberg 



Upon examining the stomachs of a number of tadpoles caught 

 at the edge of Aubeenaubee Bay in August, 1906, a goodly num- 

 ber of Arcella vulgaris were obtained. The tadpoles when caught 

 were busy sucking the surface of weeds and sticks, as is their 

 habit, and from these they probably obtained the Protozoa. It is 

 probable that Protozoa form an important part of the food of 

 young tadpoles. On other occasions we have seen them taking 

 in large numbers of Paramoecium. 



Arcella vulgaris was abundant September 3, 1906, with other 

 material (Paramoecium) forming a scum over water in a tumbler 

 where some duckweeds were kept. It was also present in hand- 

 gathered material obtained at the dam in the Outlet, October 30, 

 of the same year. 



2. CENTROPYXIS ACULEATA Stein 



Taken occasionally in the summer and autumn of 1906 in gath- 

 erings in shallow water near shore. 



3. EUGLYPHA ALVEOLATA Dujardin 



Obtained in collections near shore, summer and autumn of 1906. 



4. DINOBRYON sp. 



Found occasionally near shore in Lost Lake, but not abundant. 

 In the small lakes about St. Paul, Minn., where it is very abund- 

 ant, it furnishes an important item in the food of the fresh-water 

 mussels. 



5. EUGLENA VIRIDIS Ehrenberg 



Some found in a scum in pools in Green's marsh. The great 

 amount of vegetation makes the water almost as rich as an in- 

 fusion. Obtained August 22, 1906. Euglena formed a bright 

 green scum over the small pools. 



fi. VOLVOX AUREUS Ehrenberg 



Not found by us at all in the lake, but exceedingly abundant in 

 Farrar's pond and a pond east of the lake in the spring of 1901, 

 large swarms being seen there, a single dip of a common dipper al- 

 ways containing several examples. A large number of examples 

 obtained from a small pond near the lake April 24, 1901. Its 

 favorite habitat is shallow pools, easily warmed throughout and 

 containing in the bottom an abundance of dead leaves or similar 

 fertilizing matter. This species was exceedingly abundant in the 

 shallow well-fertilized carp ponds at Washington, D. C, in the 

 spring of 1906. 



