On Aquatic Carnivorous Coleoptera or Dytiscide. 477 
tarsi broad, and the unguiculi of the former modezately long, the anterior one being 
a little shorter than the posterior. 
Europe. (Finland, 68° 55’ North, Sahlberg). 339. 
617. Hyphydrus lapponum, Gyll., Hydroporus lapponum, M.C.—Oblongo-ovalis, 
sat convexus, tenuiter pubescens, fusco-niger, (limbo spe dilutiore), antennis, 
pedibus capiteque rufescentibus, hoc fuscomnotato, antennis apicem versus, plus 
minusve infuscatis ; prothorace elytris evidenter angustiore angulis posterioribus 
obtusis, limbo punctato, disco levi; corpore subtus obsolete punctato. Long. 4%, 
lat. 23 m.m. 
Mas, fere opacus, subtiliter punctatus, tarsis anterioribus latis, unguiculis elongatis, 
fere simplicibus et sequalibus. 
Fem., per-opaca, obsolete punctata, tarsis latiusculis. 
Northern Europe and Siberia. (Sweden ; Finland, to 69° North, Sahlberg). 338. 
618. Hydroporus fortis, Lec., M.C.—Oblongo-ovalis, convexus, dense subtilissime 
punctatus, evidenter pubescens, niger, pedibus fuscis, antennis elongatis fuscis, basi 
rufo ; corpore subtus fere opaco, coxis posterioribus crebre sed. obsolete punctatis ; 
abdomine fere dense punctato; prosterni processu latiusculo, sat compresso, medio 
haud carinato, anterius leviter tuberculato-prominulo. Long. 63, lat. 33 m.m. 
Mas, tarsis anterioribus et intermediis fortiter dilatatis, illis unguiculis elongatis, 
tenuibus, basi haud curvatis. 
I have seen only a single specimen of this very distinct species, for which I know 
no near ally. 
North America. 337. 
619, Hydroporus americanus, Aubé, M.C.—Oblongo-ovalis, convexiusculus, 
crebrepunctatus et pubescens, fusco-rufus, pedibus capiteque rufis; coxis posterioribus 
sparsim fortiter punctatis ; abdomine tantum basi utrinque fortiter sparsim punctato ; 
prosterni processu anterius nullo modo prominulo, Long. 4, lat. 23 m.m. 
Mas, subnitidus, elytris evidenter punctatis, tarsis anterioribus vix dilatatis. 
Fem., opaca, elytris minus fortiter punctatis. 
Aubé’s unique type of this species is a small, very red, and rather strongly 
punctured individual. 
North America ; (Massachusetts). 336. 
620. Hydroporus dichrous, Melsh., M.C.—Oblongo-ovalis, evidenter pubescens, 
crebre subtiliter punctatus, nigricans, pedibus capite thoraceque rufis ; elytris fuscis, 
3Q2 
