Sept., I917-] Fall: New Dytiscid^. 175 



in the same streams with dilatatus: it differs from the latter in its 

 generally paler yellow color, immaculate thorax, still more sharply 

 contrasting elytral markings, and especially by the impressed discal 

 lines on the elytra, with feeble intercostce. 



The following dark form has been considered a distinct species by 

 Mr. Sherman, but the agreement in all essentials with typical dilatatus 

 is so complete, that I am at present unable to see in it anything more 

 than a suffused variety. 



Var. suffusus new variety. 



Similar to the typical form in most respects except color. The basal and 

 apical thoracic dark areas are here extended and become almost confluent on 

 the median line ; dark markings of elytra broadly suffused, so as to obscure 

 or obliterate the transverse pale fascia:, which in the type are represented by 

 a single small rufous spot at their outer extremities. In other examples the 

 pale fasciae are more complete, but smaller, more obscure and broken. The 

 size is a little smaller on the average than in the typical form, and some 

 females are apparently a little duller. Length 3.85 to 4.1 mm.; width 2.1 

 to 2.3s mm. 



New Jersey (Eatonton, July 4), 3 c?"s, 3?'s, sent by Mr. Sherman, 

 who writes that it occurs in running brooks. 



Hydroporus sulcipennis new species. 



Form moderate, subovate, scarcely as broad as in undulatiis. and a littla 

 more pointed behind ; surface finely alutaceous but moderately shining in 

 both sexes, pubescence fine and thin ; punctuation above rather fine, nearly 

 uniform, the punctures separated on the average by about one and one half 

 times their own diameters, finer and sparser on the head. Color flavo- to rufo- 

 testaceous ; prothorax with the posterior margin very narrowly infuscate in 

 median half, and with or without a small diffuse fuscous spot or shade at the 

 middle of the apical margin ; elytral markings of the usual type, occupying 

 one half to three fourths the superficial area, rather sharply defined. Head 

 broadly feebly impressed each side, clypeus scarcely thickened. Antennae 

 entirely pale. Prothoracic margins narrow, scarcely wider in front. Elytrai 

 each with three longitudinal impressed lines or sulci, the middle one deepest, 

 the inner one subsutural, the outer one at the middle of the elytron. Body 

 beneath entirely pale, anterior intercoxal prominence of prosternum subob- 

 solete ; metasternum and coxal plates very grossly, moderately, closely punc- 

 tate ; the first and second ventral segments similarly but somewhat less coarsely 

 so. Front tarsi of male moderately dilated, a little more strongly so than in 

 the female, the claws equal, the anterior one a little stouter, their inner 

 margins slightly bisinuate. Length 3.5 to 4 mm.; width 1.8 to 2.1 mm. 



