On Aquatic Carnworous Coleoptera or Dytiscide. 469 
591. Hydroporus nivalis, Heer, M.C.—Oblongo-ovalis, subdepressus, tenuiter sed 
evidenter pubescens, sat nitidus, crebrius sat subtiliter punctatus, niger, pedibus 
fuscis, antennarum basi fusco-rufo; coxis posterioribus crebre evidenter punctatis, 
abdomine segmento apicali obsolete punctato sed apice summo distincte punctato. 
Long. 3%, lat. 2 m.m. 
The sexes are difficult to distinguish. The colour of the elytra sometimes becomes 
paler than the rest of the surface, but never leaves marks or spots. 
Europe. An Alpine species found from Styria to the Pyrenees: Styria, Austrian Alps, Lago Pinter, 
Hautes Pyrenees. Found once in Finland, 64° North, according to Sahlberg. 366. 
592, Hydroporus signatus, Mann., M.C.—Oblongo-ovalis, minus convexus tenuiter 
pubescens, sat nitidus, abdomine pectoreque nigris, supra fusculo, prothorace 
lateribus rufescentibus, elytris signaturis humeralibus, maculaque indistincta apicali 
testaceis, pedibus rufis, antennis fusco-rufis basi dilutiore ; prothorace ante basin 
transversim depresso, limbo subobsolete punctato, disco fere impunctato ; elytris sat 
crebre, distincte punctatis ; coxis posterioribus sat crebre evidenter punctatis. Long. 
34, lat. 13 m.m. 
The distinctions between the sexes seem to be extremely slight. 
North America, (Hermit Lake, Mt. Wn. N.H.). 365. 
593. Hydroporus longiusculus, Har., M.C.—Oblongo-ovalis, minus convexus, 
tenuiter pubescens, minus nitidus, abdomine pectoreque nigris, capite fusco-rufo, 
prothorace fusco, limbo evidenter, disco sparsim obsolete, punctato, elytris fusco- 
ferrugineis, sat crebre et fortiter punctatis; antepnis pedibusque rufescentibus ; 
coxis posterioribus minus crebre subobsolete punctatis. Long. 4, lat. 2 m.m. 
I have seen but one or two specimens in bad condition of this species. 
North America, (Unalaschka). 364. 
594. Hydroporus pyrenzus, Wehncke, Berl. Zeit. XV, p. 163.—Oblongo-ovalis, 
minus pubescens, nitidus, subtus nigricans, supra paulo dilutior, pedibus rufo- 
obscuris, antennis fuscis basi rufo ; prothorace angulis posterioribus obtusis, disco 
levi, limbo minus distincte punctato ; elytris parcius sat fortiter punctatis, coxis 
posterioribus parce minus fortiter punctatis. Long. 32, lat. 17 m.m. 
This species is closely allied to Hydroporus morio (No. 598), but is rather 
narrower and more elongate, more shining, and with the thoracic punctuation 
considerably less. I think the type sent me by Herr Wehncke is a male, the tarsi 
are not quite so broad as in Hydroporus morio, and the claws of the front ones are 
not dentate, but slightly elongate. 
Europe: (Pyrenees). 362. 
