On Aquatic Carnivorous Coleoptera or Dytiscidce. 439 



Group 2. 



501. Hydroporus cimicoides, n. sp. — Ovalis, latus postice acuminatus, evidenter 

 pubescens, fere opacus, dense fortiter punctatus, ferrugineus, prothorace ex pai'te 

 elytrisque fuscis, his testaceo-signatis, antennis fuscis basi testaceo ; prothoracis 

 margine crasso, duplicate ; epipleuris carinatis, corpora subtus fortiter puuctato. 

 Long. 4i, lat. 2t. 



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, Lee, 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. 21, lat. 11 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 epipleurre 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. — OvaUs, 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. 24 m.m. 



The male has the front and middle tarsi rather strongly dilated, the clf.ws of tiic 

 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. 



North America ; (Cambridge, Pennsylvania). 273. 



504. Hydroporus lobatus, n. sp. — Ovalis, minus latus, evidenter pubescens, 

 ferrugineus, antennis extrorsum elytrisque fuscis ; crebre fequaliter sat fortiter 



