182 Journal New York Entomological Society. [VoL xxv. 



Anterior claw of front tarsus acutely dentate in the male. Length 3.8 to 4.3 

 mm.; width 1.8 to 2 mm. 



Massachusetts, Tyngsboro, July-August, 5 J"s, 4 ?'s; Marion, i 6; 

 New Hampshire, Farmington, i 3. The type is a Tyngsboro male. 



The species belongs to the americanus group, but is at once dis- 

 tinguished from allies by the toothed anterior claw of the male front 

 tarsus. The species is not rare at Tyngsboro in various ponds and 

 springs. 



Hydroporus melsheimeri new species. 



Form rather broadly ovate, widest at or near the anterior third, or but little 

 behind the elytral base ; distinctly pointed behind ; color rufopiceous, becom- 

 ing gradually paler toward the sides of the elytra basally, and along the lateral 

 and anterior margins of the thorax, head rufous ; surface finely, sparsely 

 pubescent and shining. Antennae moderate, the outer joints more or less 

 infuscate. Head finely, sparsely punctate, moderately biimpressed, clypeus 

 not thickened. Prothorax rather finely margined at sides, finely, sparsely 

 punctate at middle and in front, more strongly and closely posteriorly. Elytra 

 rather finely, not closely, punctate. Beneath piceous, venter either entirely 

 rufous or with the basal segments infuscate, propleur^e and legs rufous. Front 

 and middle tarsi of male moderately broadly dilated, the claws of the anterior 

 tarsi not appreciably modified, and mutually subequal, the front claw at most 

 only just visibly shorter. Length 3.25 to 3.75 mm. ; width 1.75 to 2 mm. 



Massachusetts, Tyngsboro (type c?) and Marion; 3 c^'s, 7 $'s. 



This species is closely allied to dichrous Melsh., but is a little 

 smaller, evidently more broadly ovate, and less finely punctate. In 

 dichrous the prothorax as well as the head is as a rule uniformly 

 rufous, the venter — in fully colored examples — is piceous, except 

 narrowly at sides and tip; the front tarsi of the male are slightly 

 wider, and there is a marked sexual disparity in this respect, the 

 middle tarsi especially being conspicuously narrower in the female, 

 while in melsheimeri the middle tarsi of the female are very nearly 

 as widely dilated as in the male. In dichrous the front claw of the 

 anterior tarsus is considerably shorter than the other. 



