On Aquatic Carnivorous Coleoptera or Dytiscide. 439 
Group 2. 
501. Hydroporus cimicoides, n. sp.—Ovalis, latus postice acuminatus, evidenter 
pubescens, fere opacus, dense fortiter punctatus, ferrugineus, prothorace ex parte 
elytrisque fuscis, his testaceo-signatis, antennis fuscis basi testaceo ; prothoracis 
margine crasso, duplicato ; epipleuris carinatis, corpere subtus fortiter punctato. 
Luong. 43, lat. 23. 
In the male the front and middle tarsi are broad; the claws of the front ones 
are short, but the anterior one is evidently shorter than the other: the female has 
the punctuation of the’ upper surface more obsolete than in the male, although it is 
still quite distinct. 
North America, 272. 
502, Hydroporus mellitus, Lec., M.C.—Ovalis, latus, brevis, parcius pubescens, 
sat nitidus, testaceus, elytris lineis fuscis confluentibus obscuratis, sub-obsolete vix 
crebre punctatis ; prothoracis margine tenuissimo; coxis posterioribus fortiter 
punctatis. Long. 23, lat. 12 m.m. 
I have only seen a single specimen in bad condition of this species, and do not 
know its sex : by its short, broad form, and large head, it recalls H. cimicoides from 
which it differs by its minute size, and the delicate lateral margin of the prothorax 
and the smooth ventral segments ; I think however it will prove to be really allied 
to the species in question, and anticipate the discovery of intermediate forms. 
The prosternal process seems similar, and the epipleuree also approximate those of 
the larger species, but I cannot speak very confidently, as the individual besides 
being badly preserved is immature. 
North America ; (New England, Vermont, fide Crotch). 296. 
503. Hydroporus undulatus, Say, M.C.—Ovalis, sat latus, evidenter pubescens, 
ferrugineus, elytris fuscis, testaceo-signatis, prothorace anterius et posterius plus 
minusve infuscato, antennis extrorsum fuscis; prothorace sat tenuiter marginato ; 
subtus fortiter punctatus, coxarum punctis densis. Long. 4, lat. 2¢ m.m. 
The male has the front and middle tarsi rather strongly dilated, the claws of the 
front ones quite short ; its upper surface is a little shining, and is rather finely but 
closely punctured, while in the female the upper surface is quite dull and obsoletely 
punctured. 
bo 
a 
Ss 
North America ; (Cambridge, Pennsylvania). 
504. Hydroporus lobatus, n. sp.—Ovalis, minus latus, evidenter pubescens, 
ferrugineus, antennis extrorsum elytrisque fuscis; crebre eequaliter sat fortiter 
