212 
Wisconsin Academy of Sciences , Arts and Letters. 
The following species were noted: 
Diaptomus sicilis Forbes. 
“ minutus Lillj. 
Epischurci lacustris Forbes. 
Limnocalanus macrurus Sars. 
Cyclops fluviatilis Herrick 
“ serrulatus Fischer. 
Canthocamptus sp. 
Cypris sp. 
Daphnella brachyura Baird. 
Ceriodaphnia reticulata Jnrine. 
Daphnia kalbergensis Schoedler. 
Bosmina sp. 
Alona glacialis Birge. 
Leptoclora hyalina Lillj. 
Pontoporeia Hoyi Smith. 
Mysis relicta Loven. 
There were, besides, several forms of cyclops, which seem to differ from 
any described American species. As I am now engaged in a study of this 
genus, I will leave their description for a later publication. None of the 
species of cyclops which I have found is peculiar to the deep water, as I 
have found the same forms in the littoral zone of the lake, and in smaller 
bodies of water in the vicinity. 
The pelagic fauna consists mainly of the following species: Diap¬ 
tomus minutus Lillj; Diaptomus sicilis Forbes; Epischura lacustris 
Forbes; Limnocalanus macrurus Sars; Daphnia kalbergensis Schoedler; 
Leptodora hyalina Lillj. All of these, with the exception of limnocalanus 
macrurus , come to the surface at night. The species of cyclops are repre¬ 
sented very sparingly, and canthocamptus , daphnella , ceriodaphnia , and 
alona are quite rare. Evening collections showed vast numbers of 
diaptomus minutus and epischura lacustris , and in some cases of lepto¬ 
dora hyalina. I found bosmina very abundant in November, but rather 
rare in the summer months. The abyssal Crustacea are cypris , ponto¬ 
poreia Hoyi Smith, mysis relicta Loven, and perhaps some of the forms 
of cyclops. Especial interest, perhaps, attaches to three species of the 
preceding list. 
Diaptomus minutus Lillj. is found in great numbers, being much 
more abundant than diaptomus sicilis Forbes. My specimens corre¬ 
spond very closely to the description by Lilljeborg, as given in “ Envis¬ 
ion des Calanides d’Eau Douce,” by Guerne and Eichard, differing only 
in the following particulars. The joints of the right fifth foot of the 
male are shorter and stouter, and the terminal claw is longer and some¬ 
what more slender; the lateral spine on the last joint is blunt. The 
inner ramus of the left foot is more nearly elliptical. The animal aver- 
