442 On Aquatic Carnivorous Colecptera or Dytiscide. 
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 Hydroporus undulatus, (No. 503), but has the 
antenne nearly entirely red, the punctuation of the upper surface denser, and 
the prothoracic margin even a little finer. The coxal limes are not divergent at 
the extremity. 
North America, (Lake Superior). 277. 
511. Hydroporus eruditus, n. sp.—Ovalis, minus latus, evidenter pubescens, 
dense punctatus, ferrugineus, antennis extrersum elytrisque fuscis, his signaturis 
obsoletis, prothorace sat crasse marginato; elytris stria suturali bene distincta ; 
coxis posterioribus dense sat fortiter punctatis. Long. 49, lat. 25 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 obsclete. 
North 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. 25 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 tarsi are much more 
slender, and the punctuation of the under surface is more scanty. The coxal lines 
are distinctly divergent in front, but not at the apex. 
North America. 279. 
513. Hydroporus proximus, Aube, Spec. p. 483.—QOvalis minus convexus, sat 
nitidus, parce 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. 383, lat. 
vix 2 m.m. 
