442 Oil Aquatic Carnicorous Coleoptera or Dytiscidce. 



I have seen but a single individual, which is a male and has the front and middle 

 tarsi strongly dilated, the claws of the front ones quite small. 



This is very closely allied to Ilydroporus undulatus, (No. 503), but has the 

 antennae nearly entirely red, the punctuation of the upper surface denser, and 

 the prothoracic margin even a little finer. The coxal lines are not divergent at 

 the extremity. 



North America, (Lake Superior). 277. 



511. Hydroporus eruditus, n. sp. — Ovalis, minus latns, evidenter pubescens, 

 dense punctatus, ferrugineus, antennis extrorsum elytrisque fuscis, his signaturis 

 obsoletis, prothorace sat crasse marginato ; elytris stria suturali bene distincta ; 

 coxis 250sterioribus dense sat fortiter punctatis. Long. 42, lat. 2| m.m. 



The male has the front and middle tarsi moderately dilated ; its surface is very 

 nearly opaque and is densely and finely punctured; the female is very dull and has 

 the sculpture of the upper surface quite obsolete. 



Nortli America, (Philadelphia). 278. 



512. Hydroporus republicanus, n. sp. — Ovalis, sat convexus, minus elongatus, 

 ferrugineus, supra plus minusve infuscatus, prothorace tenuiter marginato, coxis 

 posterioribus fortiter crebre sed haud dense punctatis. Long. 4, lat. 2l m.m. 



The male is shining and has the upper surface rather coarsely and not densely 

 punctured, and the fine pubescence scanty, its front tarsi are only slender ; the 

 female is dull, and has the upper surface more infuscate, its punctuation fine and 

 almost obsolete, the pubescence almost dense and the tarsi very slender. 



I have only seen one male and one female of this species, though they are very 

 dissimilar to one another I think there is no doubt they are the sexes of one 

 species. The species is rather smaller and shorter than Hydroporus undulatus, 

 (No. 503), and the punctuation of each sex on the upper surface is more distinct 

 than in the corresponding sex of that species ; the front taisi are much more 

 slender, and the punctuation of the under surface is more scanty. The coxal linos 

 are distinctly divergent in front, but not at the apex. 



North America. 279. 



513. Hydroporus proximus, Aube, Spec. p. 483. — Ovalis minus convexus, sat 

 nitidus, parcc pubescens, ferrugineus, thorace antice macula fusca, basi elytrisque 

 infuscato-ferrugineis, his signaturis vagis obscurioribus ; elytris sat fortiter et sat 

 crebre punctatis ; coxis posterioribus fortiter haud dense punctatis. Long. 3|, lat. 

 vix 2 m.m. 



