804 
Birge—Notes on Cladocera. 
Acantholeberis curvirostris, O. F. Mueller. 
This large species, not before recognized in the United States, 
occurred in large numbers in a marshy pool near Minocqua and 
at several other localities between that town and Tomahawk, 
Wis. 
All the European genera of Macrothricidse have now been 
found in Wisconsin. They are represented by ten species, while 
in Europe fourteen have been described, but no single country 
has yielded more than nine. Of the ten, eight are identical with 
the European forms. One species, Ilyocryptus lonyiremis, Sars, is 
identical with an Australian form, although close to the European 
I. agilis , Kurz. Bunops scutifrons , Birge, is very close to B. 
serrieaudata , Daday. With this exception, all the European 
genera which contain only one species are represented in this 
country by the same species. Of European forms which might 
be expected to occur in this country, there have not yet been 
found Macrothrix hirsuticornis , N. and B., and Ilyocryptus agilis 
and acutifrons, Kurz. 
Macrothrix laticornis seems to be the most common European 
form. In Wisconsin, M. rosea , in a form close to M. tenuicor- 
nis , Kurz, is by far more abundant. In collections from 
Starkville, Miss., M. laticornis was present in great numbers 
and M. rosea was absent. 
Ophryoxus gracilis , Sars, is very generally distributed 
through the state, as is Lathonura rectirostris, O. F. M. 
Acantholeberis I have found only at the more northern stations. 
I have never found it in southern Wisconsin although I have 
looked carefully for it. I hesitate to say, however, that the 
species is not found here. In a recent paper I stated that Polyphe¬ 
mus pediculus is very rare in Madison. This had been true ever 
since I began to collect, more than twelve years ago. But last 
season it appeared in great numbers in waters which certainly 
did not contain it before. It is therefore not at all impossible 
that a similar discovery may be made for Acantholeberis. 
Drepanothrix dentata , Euren, has been found only in lake 
Wingra, Madison, Wisconsin, and at Washington Harbor, Isle 
Royale, Michigan. It probably occurs in the region between 
these points, which are separated by more than 300 miles. 
