l'o4 FAiriLY VI. — IIYDHOPIilLID,??. 



tiuelj- auil sijarsely imnctate, its sides broadly flattened; median gi-oove 

 wide and deep, discal foveiu separated, the hind nnes oblique and larger 

 tiian those In front ; lateral ones broad, shallow and but slightly tuiTed. 

 Elytra with rows of large quadrate punctures. Length 1.5 mm. 



Putnam County; rare. October 17. Sifti-d from debris at side 

 of hillside spring, ilr. Blanchard, who compared the specimen 

 with those at Cambridge, writes that "the short convex form is 

 quite different from any of our named species." 



IV I-lYnR.ENA Kug. 1794. (Gr., "to wash or bathe.") 



Our single member of this genus is smaller than any of those 

 belonging to the two preceding genera. The thorax is subquadrate, 

 about three-fourths the width of elytra, and the latter are marked 

 with more than ten rows of punctures. 

 4,s<i (l.'M'i. HyDE-EXA PENNSYLVAXiCA Kies.. Ijnn. Entom., lY, ls4i'., lur,. 



Eldiii^ate-oblou.s. subcoiivex. I'iceous or dark leddish-brown, the palpi. 

 lei;s and narroxA- side margins of thurax dull yellow. Thorax narrower at 

 base than aptx. side margins sinuate ; disk c jarsi'l.v and densely punctate 

 and with a laru^e Impiessii.n each side near front an^xles. Punctures of ely- 

 tral stri.c cluse. rather coarse, quadrate; intervals narrow, convex. Length 

 l.N-2.2 mm. 



Kosciuskd Coimtv; scarce. June 24. Sifted from damp, de- 

 caying sphagnum moss in tamarack swamp. 



Tribe II. HYDUOPIIILINI. 



Large or medium si zlxI beetles of au oval or elliptical convex 

 fdrm. olive-black in color, rarely with sides of thorax and elytra 

 yellow. Elytra not striate; antenna' Q-joint^d; meso- and meta- 

 sterna forming a continuous keel which is prolonged behind into an 

 acute spine; middle and hind tarsi strongly compressed, fringed on 

 the inner side with long hairs. Three genera occur in Indiana. 



KEY TO GEXEKA OF HYDKorHILlXI. 



((. I'msternum snliate; metasternal spine long. 



6. Length D.". or more mm.; last joint of maxillary palpi shcirter than 



the preceding. y. Hydrophill s. 



hi). Length less than 12 nmi. ; last .loiut (if maxillary jialpi equal to or 



longer than jireceiling. A'l. TnonsTEKxrs. 



nil. Prostei-num carinate; metasternal spine short: leii-rh i:;-lii mm. 



VII. Hydrocharis. 



V Hyduophius (ieoff. 17(i4. ((Jr.. "water * hiving.") 



This genus includes two very Inrge black lieetles. the giants of 

 the family as repi-esenled in North America. 



