304 Birge — Notes on Gladocera. 



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 longiremis, Sars, is 

 identical with an Australian form, although close to the European 

 I. agilis, Kurz. Bunops scutifrons, Birge, is very close to B. 

 serricaudata, 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. 



Ophryoxns 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 clentata, 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. 



