238 Proceedings of Indiana Academy of Science. 
Peridinium, the horns or projections, which are the distinguishing char- 
acteristics, occurring in all degrees of development. 
8. Ceratium macroceras Schrenk 
Common in the vertical plankton hauls, occurring in the great ma- 
jority 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 developed perhaps as much to 
give buoyance to the form as for protection. The Peridinales, repre- 
sented by this and the two preceding species, are claimed by both botan- 
ists and zoologists. 
9. Stentor ceruleus Ehrenberg 
While raking up weeds through a hole in the ice at the Weedpatch, 
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 Janu- 
ary 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 ceruleus. 
On February 7, on looking through the ice on Outlet Bay, it seemed 
full of a reddish fine material like stirred-up mud. Examination re- 
vealed 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 attached 
to the under side of lily pads in Hawk’s marsh. 
11. Vorticella chlorostigma Ehrenberg? 
On June 26 (1901) white, fluffy little globules, which shrank to 
minute size when touched, and which proved upon examination to be 
composed of colonies of Vorticella, were found very abundant on the 
submersed tips of Ceratophyllum leaves at the Inlet. Late in the autumn 
of 1904 (October 31, November 2 and 16), the same objects were noted, 
but in considerably longer and larger patches, on various weeds, such 
as Myriophyllum, ete., in the vicinity of Winfield’s. Again, in the 
autumn of 1906, they were exceedingly abundant in various weeds, 
especially dying leaves of Vallisneria, in Outlet Bay. So far as we 
have observed, these organisms seem to increase greatly during the 
autumn. Both white and green colonies were found, alike in everything 
except color, and it is probable that they were the same species under 
different conditions. The green forms showed distinctly against the 
dead Vallisneria leaves, which had faded to a papery white. It may be 
