THE 



AMERICAN NATURALIST 



Vol. XLI August, 1907 No. 488 



OBSEin'ATIOXS OX THE NATURAL HISTORY OF 

 DIVING BEETLES 



JAMES G. X1:E])HAM AXD IIKLl' X V. A\ ILLTAMS( )X 



Our predacious diviner l)eede? of the family Dytix idie are 

 fairly well known as niuseuiii species, hm the >tudy of their life 

 histories and hahits ha- hceii -inuularly lu'uicctcd. A nuniher 

 of our genera and a few of oui- >pe( ie> occur ai>(> in Knroi)c, and 

 the natural history of M)ine of theM' ha^ l.een Mu.lied th.-re; hut 



Therefore the foll-.^in.- oh.ervat i.Mi. on the hahits and adapta- 

 tions of the uronp may serve to direct attention to an iniworked 

 but interesting- field. 



Dvtiscida-areveryc-omitionat Lak<. Forot, an.l are verv acce->- 

 ible in a catnpn> pond that lie. almo>t mnh-r the uin<lows of ,!,c 



iuthor for that purpose with eia^-es for a nmnl.<-r of year--. TW 

 material incidentally aecuinulate<l in that work, coml.ined^ with 



author during the academic year 1 <.)().')-('), will con>titute this paper. 

 The campus pond locally known as the "(iyni Po!id'"i from 



made by damming a short, sj)rin<:'-ftMl branch of one of the ra\ ine> 

 that bound the campus. It has betMi in exi-KMice for many yeais. 

 and conditions in it are now qtiite natural. It is some sixty meters 

 long and about half as wide, an.l if attains a .l.>pth of four and a 



end it hecom.'. diallolv, and is lilled with a <lenM- an.l clear growth 



