T\\\: i'i;i;i> \('i;oi's ihxim; i!i:i:it.i:s. 



2:n 



KKY TO INDIANA Sl'KCI KS l)l" DVIISCIS. 



it. 1-iiltriiiu (lisliucl ly ('lu.ir^in.ili' .it luiddlc. 



I). Hind cdx.-il iiriiccsscs ri'iimlfd ..r .Miitf. imt spiiinsc. 



c. Tliui-iix with sides yflli^w. hnsc .-iiid npcx not or nidy iiidisi iiictly so. 



(/. Abdiiiuiiinl sc.miuMits roddisli-lM-n\vn with :i piccous liiiul inargin; 



clytni of liMiinlc .•il\v:iys sul<;it.'. 1 Jit. fasi'IVENTkts. 



(/(/. .\lid(.iiiin;il s.'uMifiiis iiniliM-iii \>\:\rk itv pict'inis: clylr.-i i>\' rcinalcs 



SUHHitll. 



('. Ely(ni willinnl :i nari-dw siiliaiiic-i I miss-hai' .>t' \cll«i\v; siiiallci'. 

 L'.") I'T nun. 4''0. iiviiUiDis. 



re. i:iyti-a willi .1 naiTow (ilil'upir snliaidcal cross-bar; larger, :!L' 

 :;-, inin. -151. vkrticalis. 



(■<■. 'I'liorax with t)as(' and ajirx. as well as sides, (listiiictly aiul ratli<M- 

 broadly yellow; I'eniales dinMiripliic. 

 /. Hind coxal jtrocesses acnte; ItMi^tii :v.\ nun. makginaos. 



//'. Hind coxal processes obtnse ; lenutli :!() nnn. sitblimbatus. 



Jth. Hind coxal iirocesses produced, distinctly spinose; thorax with base, 

 ajiex and sides broadly yellow ; length I'A :\7> inui. dauricus. 



(III. I.abrnni nearly trnncate at middle: tlmi'ax with all the margins dis- 

 tinctly and broadly yellow: females dimoriihic. 452. iiARUisii. 



4411 ( 1 |s1 I. Itviiscrs i-AscivKxrins Say, L<ing's l']xped., II. 

 I'Tii; ibid. I. 177. 

 Elongate-oval, (ireenish-black .above; thorax margined 

 with yellow only on the si<les. or with a taint trace of yel- >< 

 li.w at base and apex. i:iytra of female each with ten H 

 t:i-(i<ives whi<-h reach beydnd the middle; their apical third ^ 

 finely and rather densely pniict.-ite. Length '_'.") lis nun. (Fig. 

 lie.) 



Dekall) niid Marion coutitios; fi'(>(|neiit. A]ii'il 10- 

 July 18. 



Fig. 116. 

 Natural size. 



4.'')0 (17S2). DvTTScrs iiYiiRims Anbe. Sjiec. (len., VI, 1S:1S. 110. 



Iicgnlarly ovate. Thorax slmrtei' than in fiisrirciifrix. the ajiex usually 

 narrowly yellow and snmetimes with a faint .\elli.\v line at l)ase. Tale mar- 

 gin of elytra of nearly e<iual width thr aigliiput. Lcnglli lid 2S mm. 



Lake. Lai)()i't('. Staiko. Yi<;'o and I'oscy coiintii^s; tV('(|nent. 

 .Vprii irj-Seploiubei" li). 



4.".1 (14s:',). Dytiscis vkkticai.is Say. Ti-ans. .Vmer. I'hil. Soc.. II. 1S2:5. 

 •12; ibid. II, m\ 

 Oval, rather broad. Thorax maigined with yellow only on sides. Ely- 

 tra with three rows of well marked dorsal punctures; the marginal yellow 

 line narrowing on apical half, the subapical line often somewhat indistinct. 

 Length ;'>:'> M.") nnn. 



Beach of Lake Micliioan near .Millers. Lake Connty: scarce. 

 :\Iav 28. 



