228 Proceedings of Indiana Academy of Science. 
Species. Per cent. 
Diaptomus oregonensis Lilljeborg.............- 0.38 
Cyclops leuckartt; (edax Forbes)............:. Asielt 
Diaphanosoma leuchtenbergianum Fischer...... 0.40 
Daphnia retrocurva Forbes, var.............:. 1.06 
Daphnia hyalina Weydig.... . 062 6c 2 see wes so 3 0 as 84.02 
BE GELS Sess eae ee cei ca aval oy pat ratow ore foe ete ences 99.97 
The Copepods (free-swimming species) frequently bear attached 
Protozoa, sometimes in such numbers as to make them appear bristly. 
They seem to be more abundant in winter when the lake is covered with 
ice. Whenever holes are cut through the ice these crustaceans often 
come crowding to the light and air. 
The Cladocera are, generally speaking, the larger and more showy 
element of the crustacean plankton. Their stomach contents, which at 
times forms conspicuous masses, was found to be composed largely of 
phyto-plankton elements, especially Botryococeus brauni, which, because 
of its color, was easily recognizable. One of the smaller Cladocera, 
Chydorus, was found to constitute an important part of the food of the 
Unionidze or mussels of the lake, as it also does of the small fishes. 
One of the most notable species of the Zoo-plankton was Leptadora 
hyalina. This is usually a deep-water species, but on September 2, 
1906, it was taken in quantities in a surface tow-net in Outlet Bay. 
Though one of the largest of the plankton crustaceans, this species was 
so transparent as to be quite invisible except by its movements among 
the associated individuals of Lyngbya. 
Jwo other species of Entomostraca not usually classed as plankton 
were noted, namely, the fairy shrimps. One, Branchippus serratus, was 
found dead in large numbers floating on the surface in deep water July 
11, 1899. Later in the same day considerable numbers were seined in 
shallow water off Norris Inlet. Again, on August 21 and 31, a few 
were seen floating. 
Another species, Branchippus vernalis, was found abundantly in 
small temporary ponds west and south of the lake in the spring of 
1901. A school of these curious crustaceans of delicate structure and 
pearly appearance, apparently usually swimming on their backs, their 
numerous gill-feet moving rapidly in the water, makes a very pretty 
sight. 
The Parasitic Copepods are reported on by Dr. Wilson. It may 
be here remarked that, as compared with other bodies of water, 
these forms are comparatively rare in Lake Maxinkuckee. In certain 
rivers which we have examined, particularly the Kankakee, Maumee, 
and sloughs along the Mississippi, certain large species of Lernasocera 
