THE PROTOZOA OF LAKE ERIE. 
113 
61. Trichodina pediculus Ehr. On Diaptomus from towings in Put-in Bay Harbor; on Hydra from 
East Harbor, Lake Erie. 
62. Vorticella convallaria L. Very abundant on algse from East Swamp, South Bass Island, 
63. Vorticella chlorostigma Elir. Forming large green patches visible to the naked eye, on the 
vegetation from East Swamp, South Bass Island. 
64. Vorticella rhabdostyloides Kellicott. Common on Anabcena in towings from Lake Erie. 
65. Zoothamnium arbuscula Ehr. In surface towings in Put-in Bay Harbor, Lake Erie, attached to 
floating matter. 
66. Epistylis plicatilis Ehr. Abundant on Cham from East Swamp, South Bass Island, in company 
with Megalotrocha alboflavicans. 
67. Vaginicola crystallina Ehr. On aquatic plants from East Swamp, South Bass Island. What 
seems the same form is often found on Fragillaria in towings from Lake Erie; these specimens 
are always much smaller, however. 
SUCTORI A. 
68. Acineta mystacina Ehr. On floating floccose material taken with the tow net in Put-in Bay 
Harbor, Lake Erie. 
While the fauna inhabiting - the plants of the bottom and about the shores of this 
part of Lake Erie is very rich in Protozoa, both in the number of species and of 
individuals, the open waters of the lake contain very few. Though 22 species are 
included in the list, as taken from the waters of the lake away from shore, most of these 
were present in very small numbers, and none were abundant. The species of the 
foregoing list found in the open waters of the lake, and on that account apparently 
to be considered limnetic, are the following: 
Amoeba proteus. 
Amoeba rillosa. 
Amoeba radiosa. 
Pamphagus hyalinus. 
Cochliopodium bilimbosum. 
Difflugia corona. 
Difflugia globulosa. 
Arcella vulgaris. 
Acanthocystis chwtophora. 
Oikomonas termo. 
Euglena viridis. 
Colacium steinii. 
Colacium vesiculosum. 
Peridinium tabulatum. 
Tintinnopsis cylindrica. 
Codonella cratera. 
HolosticUa mystacea. 
Trichodina pediculus. 
Vorticella rhabdostyloides. 
Zoothamnium arbuscula. 
Vaginicola crystallina (?). 
Acineta mystacina. 
This list includes a number of species not usually recorded from open-lake waters; 
these are chiefly due to Professor Reighard’s collections with the water bottle, which 
were made as follows: A large corked bottle was sunk in the lake to the desired 
depth, the cork pulled from the mouth, and the water allowed to fill the bottle. The 
water thus secured was then filtered, so as to prevent the escape of even the most 
minute organisms. Collections were thus made from the open lake 1 mile from any laud, 
where the water was 6 fathoms deep. Water was taken from the surface layer not 
more than 3 feet below the surface. Collections so made contained regularly a number 
of minute Protozoa not usually accounted limnetic, namely: 
Amoeba proteus. Cochliopodium bilimbosum. Peridinium tabulatum. 
Amoeba villosa. Difflugia globulosa. Tintinnopsis cylindrica (only once). 
Amoeba radiosa. Euglena viridis (once). Holosticha mystacea. 
The list is remarkable especially for the three species of Amoeba and one of 
Cochliopodium. These rhizopods are very minute, and would be lost by the usual 
methods of collecting. Continued thorough plankton work of the sort carried on by 
Professor Reighard may show that these are proper members of the limnetic fauna. 
Difflugia globulosa was one of the very commonest limnetic forms in all sorts of 
collections from the open lake. 
F. C. B. 1899—8 
