On Aquatic Carnivorous Coleoptera or Dytiscide. 397 
386. Dytiscus versicolor, Schall. Act. Hal. 313, Zydroporus reticulatus, M.C.— 
Breviter ovalis, convexus, sat nitidus, sine pubescentia, ferrugineus, elytris vittis 
interruptis nigris; creberrime subtilissime punctatus, elytris punctis majoribus 
adspersis ; processu prosternali antice acute elevato. Long. 33, lat. 2 m.m. 
The black marks on the elytra of this species consist of interrupted lines, and 
vary greatly in their extent. I do not see any sexual distinctions. 
Northern and Middle Europe : ascends, according to Sahlberg, to 65° 55’. 181. 
387. Hyphydrus quinquelineatus, Zett., Hydroporus quinquelineatus, M.C._— 
Breviter ovalis, convexus, nitidus, sine pubescentia, ferrugineus elytris lineis 
elongatis nigris ; prothorace parce subtiliter punctate, elytris sat crebre et fortiter 
punctatis, punctis minutis inter majores adspersis ; processu prosternali antice 
depresso. Long. 3, lat. vix 2 m.m. 
Europe ; Lapland, South Scotland, South Ireland, Belgium, Alsace, (Kasan, Wehncke). Ascends to 
68° 30', according to Sahlberg. 182. 
388. Hyphydrus decoratus, Gyll., Hydroporus decoratus, M.C.—Brevis, ovalis, 
latus, convexus, sine pubescentia, nitidus, piceo-ferrugineus, elytris obscurioribus, 
lateribus maculisque indistincte rufescentibus; elytris minus crebre sat fortiter 
punctatis, punctisque minoribus inter majores adspersis. Long. 23, lat. 14 m.m. 
Middle Europe, (South Sweden, England, Germany, France). Not a common species. 184. 
389. Hydroporus acaroides, Lec., M.C.—Subrotundatus, subtus convexus, sine 
pubescentia, ferrugineus, pectore abdomineque plus minusve infuscatis (vel etiam 
nigris), elytris nigro-signatis ; elytris dense fere subtiliter punctatis, versus latera 
plicula elevata abbreviata; pectore dense fortiter punctato, abdomine haud prnctato 
sed alutaceo, opaco. Long. 2%, lat. 1s m.m. 
The colour in this species appears to be variable, especially on the ventral 
seoments ; the species may, be readily distinguished amongst its allies by the elytral 
fold, and the peculiar sculpture of the ventral segments. The tarsi of the male 
though not broad are distinctly dilated ; the female I am unacquainted with. 
North America, (Western States). 178. 
Group 2. 
390. Hydroporus musicus, Klug, M.C.—Breviter ovalis, convexus, nitidus, sine 
pubescentia, ferrugineus, elytris lineis plus minusve interruptis nigris, prothorace 
crebre evidenter punctato, elytris crebre fortiter fere wqualiter punctatis. Long. 
3? lat. 24 m.m. 
a} Ut) 9 
