On Aquatic Carniv)rous Coleoptera or Di/tiscidce. 42:3 



obsoleta; subtus dense reticulato-punctatus, coxis posterioribus interne punctis 

 majoribus conspicuis ; protborace basin versus nullo modo angustato, angulis 

 posterioribus rectis ; elytris bumeris emarginatis. Long. 43, lat. Si m.ra. 

 I do not see any evident sexual distinction in tbis species. 



Central and Southern Euroi>e ; (Black Forest; GranJe Chartreuse; Alps; Pyrenees; Reynosa ; 

 Italy), 304. 



459. Hydroporus platynotas, Genu., M.C. — Subquadrato-ovalis, niger, opacus, 

 subtiliter in'uinoso-pubescens, antennis pedibusque rufescentibus, dense subtilissime 

 punctatus et supra, praesertim in elytris, fortiter punctatus ; elytris sulca basali 

 longitudinali subobsoleta ; subtus dense subtiliter reticulato-punctatus, coxis 

 posterioribus interne punctis majoribus minus, vel vix, conspicuis ; protborace basin 

 versus baud angustato, sed angulis posterioribus subrotundatis. Long. 4, lat. 

 2 J m.m. 



Tbe sexual characters are but slight, the male is rather narrower than the female, 

 and has the middle joints of the antennae more developed and the thorax a little 

 straisfhter at the sides. 



o 



Central Europe ; (apparently confined to Germany). 303. 



460. Hydroporus bicostatus, Schaum, M.C. — Oblongo-ovalis, nigricans, vel 

 rufescens, opacus.. subtilissime pruinoso-pubescens, thorace elytrisque fortiter crebre 

 punctatis, elytris medio costa longitudinali, elongata, bene elevata, aliaque externa, 

 abbreviata, obsoleta; subtus dense subtiliter reticulato-punctatus, coxis posterioribus 

 punctis majoribus sparsis sat conspicuis ; protborace basin versus baud vel vix 

 angustato, angulis posterioribus baud rotundatis. 



Mas, angustior, nigricans. Long. 4l, lat. 2l m.m. 



Fern., latior, rufescens. Long. 5, lat 2| m.m. 



Besides the difference in colour and stature, tbe male has the thorax not narrowed 

 towards the base, and has a minute tubercle on the presternum, while the female 

 is without this tubercle, and has the thorax just a little narrowed from the middle 

 to the base. 



Spain and Portugal, but very local ; in running streams. 302. 



461. Hydroporus latus, Steplj., M.C. — Latiusculus, minus depressus,''subopacus, 

 ferrugineus, vel fusco-ferrugineus, elytris magis fuscis bumeris rufescentibus, 

 antennis pedibusque dilute rufis ; tenuissime vix jierspicue pubescens, corj^ore 

 subtilissime dense punctulato, sed supra punctis majoribus, profundis, numerosis 

 conspicuis adsperso. Long 4i, lat. 21 m.m. 



In tbe male the front and middle tarsi are still broader than they are in the 



