i.i' 



Oh Aquatic Carnivorous Coleoptem or Dytiscidce. 



Mesial line between coxal pro- 

 cesses, not iu the least abbre- 

 viated at apex behind, vide 

 Plate vii., fig. 48. 



Mesial line between coxal pro- 

 cesses more or less abbreviated 

 at hind extremity, vide Plate vii., 

 fig. 49. 



r Group 1. 



-| Hind coxal cavities not quite approximate, wing cases variegate. 



( (North American species), Nos. 495 to 500. 



i 



Gi-bup 2. 

 Hind coxal cavities quite approximate, thoracic side margin 

 generally thickened, tarsi with third joint much lobed, and 

 under surface red. (North American species), Nos. 501 to 521. 



/" Group 4. 



J Hind coxal cavities quite approx., thoracic side margin not 

 \ thickened, under surface nearly or quite black, prosternal 

 (^ process short or moderately long. Nos. 552 to 629. 



Group 5. 

 Hind coxal cavities quite approximate, prosternal process elongate. 

 No. G30. 



( Group 6. 



-, Iliud coxal cavities minutely sepai-ated, surface unicolorous, pros 



( ternal process small. Nos. G31 to G36. 



( Group 7. 



•; Hind coxal cavities distinctly separated, surface unicolorous, pros- 



( ternal process large. Nos. 637 to 639. 



{ Group 8. 



• Hind coxal cavities very distinctly sepai'ated, prosternal process 



( small. Nos. G40 to 644. 



( Group 3. 



I Wing cases variegate. Nos. 522 to 551. 



i Group 9. 



• Wing cases not variegate, coxal lobes highly developed. Nos. 

 ( 645 to 649. 



California. — -Hydroporus lateralis. Boh. (No. 1392), gen. dub. ; CafTraria. — Hydroporus lor.gulus, Muls. 

 (No. 1394), near No. 632 ; France. — Hydroporus lucasi, Reiche (No. 1395), near No. 569 ; Algeria. — 

 Hydroporus melancholicus, Motsch. (No. 1398); Kamtschatka. — Hydi'oporus monilicornis, Sahl. (No. 

 1400), near No. 562; Lapland. — Hydroporus multiguttatus, Regt. (No. 1401), near 5G9 ; Syria. — 

 Hydroporus mutatus, Har. (No. 1402), gen. dub.; Natal. — Hydropoi-us niger, Say (No. 1404); North 

 America. — Hydroporus notabilis, Lee. (No. 1405), near No. 628 ; North America. — Hydroporus nudatus, 

 Say (No. 1406), 1 near 525 ; Mexico. — Hydroporus obtusipennis, Sahl. (No. 1408) ; Lapland. — 

 Hydroporus opacus Wehncke (No. 1409), 1 No. 598 var. ; Lapland. — Hydroporus opjiositus. Say 

 (No. 1410), near No. 513 ; North America. — Hydroporus persimilis, Crotch (No. 1413), near No. 638 ; 

 North America. — Hydropoiiis piceus, Steph. (No. 1414) ; England. — Hydroporus planatus, Mann. 

 (No. 1416) ; North America. — Hydroporus politus, Macl. (No. 1417) gen. dub. ; Australia. — Hydroporus 

 productus, Fairm. (No. 1419) ; Algeria. — Hydroponis puberulus, Lee. (No. 1421),? = No. 1348; North 

 America. — Hydroporus pulcher, Motsch. (No. 1423) 1 near 522 ; North America. — Hydroporus roffi, 

 Clk. (No. 1424), near No. 527; Mexico.— Hycboporus rufinasus, Mann. (No. 1425), near No. 602; 

 North America. — Hydroporus sabaudus, Fauv. (No. 1426), near No. 612 ; Europe. — Hydroporus 

 sedilloti, Regt. (No. 1428), near No. 544; Syria.— Hydroponis sei-icatus, Say (No. 1432), near No. 503 ; 

 Mexico. — Hydroporus subalpinus, Th. (No. 1434), near No. 561 ; Sweden. — Hydroporus submuticus, 

 Th. (No. 1435), near No. 601 ; Sweden. — Hydroporus subtonsus, Lee. (No. 1437), near No. 602; North 

 America. — Hj-droporus thoreyi, Clk. (No. 1442), gen. dub.; Australia. — Hydroporus derelictus, Clk. 

 /No. 1443)? No. 612 var.; Scotland. — Hydroporus truncatus, Mann. (No. 1444); North America. — 

 Hydroponis undecimmaculatus, Clk. (No. 1446), gen. dub. ; Australia. — Hydroporus vaticollis. Boh. 

 No. 1449), gen. dub. ; CafTraria. 



