476 On Aquatic Carnivorous Coleoptera or Dytiscide. 
Mas, subopacus, sat distincte punctatus, tarsis anterioribus et intermediis fortiter 
dilatatis, illis unguiculis ineequalibus, anteriore crassiore et magis curvato. 
Fem., opaca subobsolete punctata. 
This species is extremely closely allied to Dytiscus palustris, but is rather larger, 
and has the elytra less distinctly marked with yellow, and the disparity between 
the sexes greater, the punctuation being more different in the two sexes, and the 
male tarsi broader. It 1s I believe a subalpine species. 
Europe, (Pyrenees and Cantabrian mountains). 343. 
614. Dytiscus erythrocephalus, Linn., Hydroporus erythrocephalus, M.C_—Ovalis, 
convexus, subnitidus, evidenter pubescens, nigricans, elytris fuscis basi lateribusque 
dilutioribus, pedibus capiteque rufis, hoc fusco-notato, antennis rufo-fuscis, basi 
rufo ; prothoracis limbo fortiter disco subtiliter punctato; elytris coxisque poster 
ioribus fortiter punctatis. Long. 4, lat. 2 mm. 
Mas, tarsis anterioribus et intermediis dilatatis. 
Fem., tarsis anterioribus et intermediis angustulis. 
Fem., var. opaca, obsolete punctata. 
The obsoletely punctured form of the female was considered a distinct species 
by Aubé and others, (I. deplanatus, Gyll.) 
Central and Northern Europe ; Siberia, (Sweden ; Finland, to 68° North, Sahlberg ; Britain ; France ; 
Germany ; Portugal, Van Volxem, this locality requires confirmation), 341. 
615. Dytiscus rufifrons, Duft., Hydroporus rufifrons, M.C.—Oblongo-ovalis, con- 
vexus, subnitidus, parcius pubescens, nigricans, elytris fuscis basi seepe dilutiore, 
antennis pedibusque rufis, illis versus apicem infuscatis, capite anterius rufescente ; 
prothorace limbo fortiter disco subtiliter punctato; elytris coxisque posterioribus 
fortiter punctatis. Long. 5, lat. 25 m.m. 
Mas, tarsis anterioribus et intermediis leviter dilatatis. 
The male differs only from the female by the rather slight dilatation of the four 
anterior feet. 
Northern Europe. (Sweden ; Finland, to 68° North, Sahlberg ; Scotland, England, Northern France, 
Belgium, Germany). 340. 
616. Hydroporus rubripes, Sahl., Not. fenn. XIV, p. 151.—Oblongo-ovalis, sat 
convexus, crebre evidenter punctatus, parcius tenuiter pubescens, sat nitidus, 
nigricans, pedibus antennisque rufis, his versus apicem infuscatis ; prothorace angulis 
posterioribus obtusis, disco leevi limbo evidenter punctato ; coxis posterioribus parcius 
subobsolete punctatis. Long. 4%, lat. 23 m.m. 
I am acquainted with the male only of this species, it has the front and middle 
