— 192 — 



(1\ KKIK.S Jh-llllc. 

 G. sinuatus I.ec. — <Juincv, 111. (also Cal.j 



HVDROI'HII.ID.K. 

 'I'iiis family iiicliRles genera of different habits. 



Hi.i.oi'HoKis J^'ahr. 



These ai^e water beetles found clin;^ing to aguatic plants and when dislodged 

 they must tloat on tb.e surface, until brought in contact with another stem or leaf. 



H. lacustris Lcc. — N. V. City and viciniiy, N. J., Lake Superior, Canada. 



H. obscurus I.,l. — Taken in this vicinit\- on Staleii Island. ('anatla 

 I Harrington), (also Calif. ). 



H. linearis Say. — Buffalo, N. \'. (Keineckel, (also liud. l!ay). 



H. lineatus .s;m'. — \. V. City ami viciniiy, N. |., Middle States, Oiiii), Lake 

 Su[)eri()r, I'an. (also Xcb.). 



H. tuberculatus (/']'//. — N. L, tare, N. 111., ('an., Mich., Lake Superior, 

 Wise, (also Europe and Asia). 



HvDRocHi's Leach. 



H. scabratus Miils — N. \'. City and vicinity, N. L, Middle and Southern 

 States (also la). 



H. rugcsus Mills. — Middle States. 



H. inaequalis l.ci. — N. \. City and vicinity, \. J., (also La). 



H. subcupreus Rand. — X. V. City and vicinitv, X. L, Can., (Harrington . 



H. variolatus Lcc. — N. J. (also Ta. and Cal.). 



H. sqnamifer /.<v.— Uuffalo, X\ Y. (Reinecke), (^)uebec. Can. (Couper). 



H. simplex /.iv . -lUiffalo, N. Y. (Reinecke). 



( )cni'Hi-:r.iLS Lrach. 



Live on the uniler side of stones in clear running shallow water. 



O. benefossus I.ec. — On the N. J. list, Yl. (Roberts). 



O. nitidus l.cc. — I'a., Lake Superior. 



O. foveicollis /,,v. — I'a. (also Fia. and N. Mex.). 



Ihl)K.KN.\ A'//i,'. 



Live in the mud of pond bottoms ami on a(|uatic plants under water. 

 H. pennsylvanica h'ii-s. — Not rare on Stafen Island, X. J., Lake Superior, 

 Can. falso Wyom. I. 



Swim freely in the ponds like I)ytiscida\ bill with less power. 



H. ovatus G. ^ //.^Kare on Staten Island, X". ^■., X. |., I'.t , ' '■ Inot lare 

 in Washington, I). C.I. 



H. triangularis Sny. — N'. K. .\iner. (the whole U. S. ) not rare in X. Y. City 

 and \iciniiy at electric lights. 



