30 
Bulletin Wisconsin Natural History Society [Vol. 13, No. 1 
Fischer ( H . weismanni Imhof) from Finmark and Ziirichsee shows 
that H. septentrionalis very closely resembles the former but is 
readily distinguished by the trilobate processes on the genital 
plate of the female and by the symmetry of the third and fourth 
pairs of swimming feet in the male. The asymmetry of the 
second feet of H. septentrionalis is of a different type than found 
in its relative, H. borealis. The third and fourth feet on the right 
Fig. 6. Heterocope septentrionalis n. sp. Second Feet of the Male, 
Showing Asymmetry. 
side of the male do not show the peculiar modifications so charac- 
teristic of H. borealis . 
This is the first authentic record of this genus for the Western 
Hemisphere. The four species of this genus hitherto described 
have been taken in northern Europe, in some of the Alpine lakes, 
and in Siberia. The genus is boreal and even arctic. We have 
also found the species in material from within the Arctic Circle 
on the Alaskan mainland. 
