Page:Memoirs on the coleoptera (IA memoirsoncoleopt01case).pdf/17

Rh

Though represented only by the female, this species is so distinct in its structural characters that it could not be mistaken; the male characters would probably decide whether it is to be properly associated with the other species of the subgenus or not; it is certainly remarkably different from them in general appearance and all characters except the very broad sterna.



This subgenus of Atheta is related to Stethusa and has the same very broad and apically arcuate process of the mesosternum, but it is here shorter and separated from the metasternum by a longer interval. The eyes are much smaller, being at nearly their own length from the base of the more parallel-sided head, the outer antennal joints much shorter and more transverse, with the last greatly elongate, being almost as long as the three preceding combined; the male sexual characters are materially different and more complex. Of the three described species, borealis Csy., is unfortunately founded upon the female, but it may be distinguished from alutacea Csy., by the more sparsely punctulate and puberulent and more polished integuments; dentata Bernh., has the head and prothorax relatively smaller and more transverse, with the protuberance of the fifth male tergite very much smaller and of different form. The following is another species: