Lake Maxinkuckee, Physical and Biological Survey 97 



7. PERIDINIUM TABULATUM Ehrenbcrg 



Taken rather less frequently in the vertical hauls than its rela- 

 tive, Ceratium macroceras, and apparently not very common. One 

 might naturally expect it to be more common near shore. It was 

 not noted often in surface hauls. It is a species of world-wide dis- 

 tribution, and probably is abundant where conditions are favorable. 



There is very little difference between the genera Ceratium and 

 Peridinium, the horns or projections, which are the distinguishing 

 characteristics, occurring in all degrees of development. 



8. CERATIUM MACROCERAS Schrenk 



Common in the vertical plankton hauls, occurring in the great 

 majority of hauls, but not common in the surface towings. A 

 similar form, C. tripos, was collected in towing near shore at 

 Eagle Lake. The long horns or projections of this species are de- 

 veloped perhaps as much to give buoyancy to the form as for pro- 

 tection. The Peridinales, represented by this and the 2 preced- 

 ing species, are claimed by both botanists and zoologists. 



9. STENTOR CtERULEUS Ehienberg 



While raking up weeds through a hole in the ice at the Weed- 

 patch, January 15, 1901, it was noted that the water dripping from 

 the plants turned the snow a vivid green. The snow thus colored 

 was taken home and examined and the green color was found to be 

 due to multitudes of green stentors. These were kept in a vessel 

 for some time. On January 6, they began to gather on sticks, on 

 snail shells, on the sides of the vessel, and on the under surface of 

 the water, assuming a globular form. The species was probably 

 coeruleus. 



On February 7, on looking through the ice on Outlet Bay, it 

 seemed full of a reddish fine material like stirred up mud. Exam- 

 ination revealed the presence of small diatoms and many green 

 stentors. 



10. STENTOR sp. 



Among our notes mention is made of another Stentor, larger 

 than the green one, brownish and with a large, flat, peristomal disc, 

 circular, with a side cleft like a water-lily leaf. 



On October 14, 1907, it was noted that brown stentors were at- 

 tached to the under side of lily-pads in Hawk's marsh. 



11. VORTICELLA CHLOROSTIGMA Ehrenber K 



On June 26, 1901, white, fluffy little globules which shrank to 

 minute size when touched, and which proved upon examination 



7— 17618— Vol. 2 



