On Aquatic Carnivorous Coleoptera or Dytiscide. 481 
Mas, sat nitidus, tarsis anterioribus et intermediis fortiter dilatatis, illis ungui- 
culis inzequalibus, anteriore crassiore, ultra medium subdentato, apice tenui. 
Fem., opaca, tarsis articulo tertio elongato. 
This species varies a good deal in colour, and especially in the extent of the 
marks on the elytra. 
Northern Europe, and Siberia, (Sweden; Finland to 68° 10’ North, Sahlberg; Britain, France, 
Germany). 342. 
Grovr 6. 
631. Hydroporus kraatzii, Schaum, M.C.—Ovalis, convexus, breviter tenuius 
pubescens, subopacus, niger, antennis pedibusque rufis ; capite latissimo ; prothorace 
disco convexiusculo, crebre punctato; elytris crebre obsolete punctatis; coxis 
posterioribus sat fortiter punctatis; tibiis tarsisque anterioribus latis. Long. 3, 
lat. 1¢ m.m. 
This species is readily distinguished from H. celatus, by the broader head and 
more obsoletely punctured elytra; I am unable to see any sexual characters. 
Europe, (Germany). 391. 
632. Hydroporus celatus, Clk., M.C.—Ovalis, haud elongatus, breviter tenuius 
pubescens, subnitidus vel fere opacus, niger, antennis pedibusque rufis; capite 
magno ; prothorace disco subtiliter punctato, elytris crebre minus fortiter punctatis, 
punctis apicem versus obsoletis ; coxis posterioribus fortiter punctatis; tibis tar- 
sisque anterioribus latis. Long. 33, lat. 1$ m.m. 
This is a variable species ; in Britain some of the specimens are duller and more 
distinctly punctured than others, and in some the elytra are rufescent towards the 
extremity, and there is also a good deal of difference in size; all the specimens 
have the legs and antenne clear red. The Piedmont specimens are smaller and 
more shining, and have the thorax rather less punctured, and the antennz some- 
what infuscate, but I do not think they are thus distinguished in a definite manner. 
The few specimens I have seen from the Pyrenees, are even more polished than 
the Piedmont variety. I do not see any sexual characters, the tarsi being broad in 
all the specimens. 
Europe, (Britain ; Seine; Pyrenees ; Macugnaga). 390. 
633. Hydroporus nevadensis, n. sp.—Oblongo-ovalis, elongatus, tenuissime 
pubescens, nitidus, niger, antennis pedibusque rufo-testaceis ; prothorace medio 
impunctato ; elytris crebre distincte punctatis, punctis ad apicem ovsoletis ; coxis 
posterioribus fortiter punctatis. Long. 32, lat. 1{ m.m. 
