366 PROCEEDINGS OF THE ACADEMY OP 



ish, and the same color extends along the inner portion of the base ; a small 

 discoidal brownish line is seen before the middle, and nearer the side than the 

 suture ; the punctures are tolerably dense and deep, and in the position of the 

 usual lines are seen a few scattered larger punctures ; the epipleurse are pale. 

 The body beneath is very coarsely punctured, as in H. suturalis and allied 

 species. 



COLYMBETES Clairr. 



C. notatus Sturm. Dytiscus not. Fabr. I have a male specimen, found in 

 Montana, which agrees with the figures and descriptions of this common Euro- 

 pean species. The head is black, with the front part and two spots on the ver- 

 tex pale. The thorax is pale, with a transverse medial black spot; the basal 

 and apical edge are narrowly margined with black ; the sides are rounded and 

 do not form a perceptible angle with the outline of the elytra. The elj-tra are 

 pale, thickly and coarsely irrorate with black, leaving the suture and two al- 

 most obsolete lines on each pale ; scutellum black. Body beneath black, legs, 

 prosternum, abdominal sutures and large apical spot testaceous. This species 

 is smaller and more convex than C. b in o t a t u s, and on account of the broadly 

 rounded sides of the thorax is more obtusely rounded in front, more parallel on 

 the sides, and more acute behind. The ungues of the anterior and middle feet 

 are very unequal, the inner one being one-half the length of the outer one, 

 which on the front feet is nearly straight. 



C. tostus, elongato-ovalis, modice convexus, antice paulo magis obtusus, 

 capite nigro antice pallido, vertice immaculato ; thorace testaceo, nebula media 

 basique infuscato, lateribus late rotundatis ; elytris lateribus subparallelis, con- 

 fertim minus subtiliter nigro-irroratis, sutura antice lineisque utrinque duabus 

 abbreviatis parum distinctis pallidis relictis ; subtus piceo-ferrugineus, pedibus 

 prosternoque pallidioribus. Long. 11mm.; hit. 5-5 mm. 



Mas unguiculis anterioribus elongatis subsequalibus, fere rectis. 



Femina elytris a basi ultra medium longitudinaliter profunde sat dense aci- 

 culatis. 



A male from North Red River, and a female from Idaho. This species has 

 nearly the form of the preceding, but is less convex ; and is easily known by 

 the absence of the vertical spots, and by the color of the under surface. The 

 inner claw of the front tarsi of the male is scarcely shorter than the outer one ; 

 they are slightly sinuous, but nearly straight. 



HELOPHORUS Fabr. 



H. fortis, elongato-oblongus, subtus nigro-piceus, supra fusco-testaceus 

 nitidus, capite virescente, punctato ; thorace parce punctato, versus latera parce 

 granulato, latitudine sesqui breviore, postice paulo angustato, lateribus 

 late rotundatis, postice subsinuatis, angulis posticis fere rectis, sulcis 5 profundis 

 exaratis ; elytris postice fusco et pallido nebulosis, striis profundis fortiter punc- 

 tatis, interstitiis parce uniseriatim punctulatis ; pedibus testaceis. Long. 5 

 0-5 mm. 



San Francisco, Mr. Bolander. Differs from II. oblong us Lee. by the tho- 

 rax being more strongly punctulate, narrowed behind, with the hind angles less 

 obtuse, and by the markings of the elytra forming a little group behind the 

 middle, the angle of which is directed forwards. The granules at the side of 

 the thorax are more distinct, and are marked with a central puncture. 



LIMNEBIUS Leach. 



L. suturalis, ovalis convexus, niger nitidus, capite thoraceque parce 

 subtilissime punctulatis, hoc lateribus fiavis diaphanis, elytris parce subtiliter 

 pubescentibus, stria suturali antice abbreviata, limbo laterali, et apicali flavo 

 diaphano, parce subtiliter, praecipue postice punctulatis ; pedibus piceis, antennis 

 basi fiavis. Long. 1-5 2 mm. 



[Dec. 



