64 UKDLH I nl.eOITIJlA. 



IIYDKADEPHAGA. 



TiiK iiiMvts iiH'hui«<l ill lhl.H MH-tiuii rf^itll■ tu Hutcr, uiul hvncv (htir lrK> ar«> Irau^^<>^nlr4i 

 intu orgnm nultaMi' Tor tuu\iti|; in lhi.<t i-lcim-ut. In atl<Iiti<>n to thi< lniU'>ri>riuuli<>ii of the 

 IfK-t Into switiiiuinij; <'rgiuu«, the Unly un«Ierg>K'i a rhuiiK*' "f f'Tiii, Ix-toiniiij^ uval <»r U*t- 

 »lii»|H'.| ; ill tliit' llu-y iirv thuntimhly BtU-d fur thi* flfiiM-m in whicli llwy an- to m'>%e, 

 iM'ini; rii.j.wi-*! with th<' nK-<in-« of ixir^iiiiii; tln-ir prry, nu«l furnl>hwl «it)ia!l th«- ron- 

 v«ini«'nor<. which ihrir c-ngMn-r* ajKin the lumi I>..^M•^•«. Alihotigh th«j r>ui>«i«t in wiil«r, 

 jret they lire n«>t i>n>viilf<l in tht-ir ix-rfoct stiitr f<>r ohtuining a ^u^>I>IJ■ »f «ir fn»iii the 

 elfniciit in which ihi-y inovr : th«y un* nir-rnnoutiiiTs, uud nrv ohligttl to ri**' orcasionRllj 

 t>> tlu' .siirfur** to obtain a supply of air for rc>-]>i ration. 



The II)UK.vuLriiAi^\ arc ]irt'ilaciou.s lK■<■tl<*^ ; and although it is not iui|N>rtaut t<> the 

 faruK T to kuow tlu-m in an economical {loiut of view, vtill yue of the larger kimb prey 

 up'Xi the ovu of n>h,auil even uiM>n their young; and in tliis resjxctjthe} are n<)l entirely 

 dtutitute of interciit to the owners of llsh-iM>nd!«. Regarded as auiinab which live l>y the 

 oha^-, lliey are truly uiore grei><Iy and gluttououi) than the predariuui laud Ux-tles : they 

 are pre-eminently voracious and destructive. Their larva-, of course, are a<juatic ; and 

 they tou feed voraciously uixm other aijuatic iusecus. Tlie jK-rfect animal, though fitted for 

 the water, is tiot confined to it : it may take wing, at evenine, and enter dwellings, like 

 mith^, iM-ing allured l>y the da/./.lini{ light of lamps near a window. The^ ohtaiu air by 

 restiiis u)>oii the surface, and raising their elytm : thi.s brings the air nion- immediately 

 Into contact with the spiracles of the ins«'Ct. 



SrcriiKN* divides the HvDRAnEPii.M^A into two families, viz : 



\vT»v\ m J '""P" »•''*<*<"»• '• cml'nwing the Dvticidx ; 

 ( dhort, clavato : enibnu-iog the Gvrimdj:. 



1. Tlie DvTiriD.r. are furnished with rather long .setaceous antemuc ; their l>odie« are 

 oval, Ixin;! n»uude<l anteriorly and {M.steriorly ; their thorax is short and transverv, and 

 their h^> are formed f>>r swimming : the p.sterior lUies, however, are esi-ecially adapted 

 to ihi'* enti, by their great length, .ind by U-ing furnished with two n.ws of denv cilia 

 arranged along the edges, w ith the v iew of increasing the width of the <>ar ; the tarsi are 

 also flat in the ftaalcs, and Uie anterior ones arv more dilated than in the females. The 

 mnn<libles of the larva are much U-nt, and are pierced for the purix»sc of extracting the 

 juici-s fmm the animals u|x>n which they subsist. Their respirati>ry organs are situated 

 behind, and consist of two segments fringed witli hairs and terminating in two c«>nical 

 ap|H'ndages, Ix-twwn which are two cylindric jM-rforatixl tul>es : these communicate with 

 the n*spirator) or>;iin«. The larva, as well a.> the imago, is obliged to rise to the siirface to 

 obtain a supply of nir. 



