176 Journal New York Entomological Society, t'^'o'- ^xv. 



Twenty-one examples are before me, from the following localities: 



New Hampshire (Farmington, August 4, type (S; Randolph, 1,300 



ft.; Sherman); Vermont (Bennington — Sherman); New York 



(Peekskill — Sherman); District of Columbia; Virginia (Ash Grove 



■ — Sherman). 



A not uncommon species, occurring always, according to Mr. 

 Sherman, and in my own experience, in running water. Sulcipcnnis 

 is very nearly related to spurkis, but is smaller and distinctly nar- 

 rower, the elytral sulci more pronounced, the punctuation of the in- 

 ferior surface even coarser. It is immediately separable from all our 

 other species of Hydroporus by the elytral sulci. 



Hydroporus semiflavus new species. 



Oval, moderately elongate, flavotestaceous, male moderately shining, fe- 

 male dull ; pubescence yellow, distinct, but less dense than in the closely 

 allied sericeus. Antennae entirely yellow, or with only the tip of the terminal 

 joint dusky. Head closely, finely punctate, clypeus evidently but not strongly 

 thickened. Prothorax similarly and not much more coarsely punctate than 

 the head, side margins moderate, a transverse fuscous spot at the middle of 

 the apical margin, the base also narrowly infuscate in middle half. Elytra 

 one half longer than wide, widest at about the basal third, rather closely punc- 

 tate, the punctures as large or slightly larger than those of the prothorax, and 

 separated as a rule by their own diameters. The markings are fuscous or 

 blackish, and consist of an entire sutural stripe dilated at middle and again 

 before the apex, a spot on each at the middle of the base, behind which and 

 narrowly separated from it is a broad longitudinal dash extending to a little 

 beyond the middle, and near its posterior end connected transversely with the 

 sutural stripe ; a shorter longitudinal spot external to the preceding and an 

 irregular transverse subapical spot. Metasternum and coxal plates coarsely, 

 rather closely punctate. Anterior tarsi rather strongly dilated, a little wider 

 in the male, in which sex the claws of the front tarsi are evidently stouter 

 and more curved, the anterior claw a little thicker and about three fourths as 

 long as the other. Length 3.8 to 4 mm.; width 1.9 to 2.1 mm. 



Illinois (Glencoe), 3 J"s, 5 $'s — type <S — sent by Mr. Sherman; 

 Missouri (Pine), a single male in my own collection, from an unre- 

 corded source. 



This species is rather closely allied to a number of others, of which 

 we may best select for comparison two neighboring species from the 

 north and west — sericeus, inhabiting the Upper Lakes region, and 

 mi.vfiis, from Kansas and Nebraska. From these and all other closely 

 allied forms (except placatiis n. sp.) scmiflaz'iis may be primarily 



