358 [June, 



undatis, elytris testaceis fusco-nebulosis, pone medium subdilatatis, profunde 

 punctato-striatis. Long. -12. 



One specimen from Fort Laramie, Nebraska. Longer and narrower tban the 

 others, and easily separated from all the following by the thorax being (as 

 in the previous ones) not at all narrowed towards the base. 



6. H. line at us, elongatus, capite granulato viridireneo, thorace testaceo, 

 viridiceneo tincto, latitudine plus sesqui t reviore, postice subangustato, et lateribus 

 subsinuato, angulis posticis rectis, parce granulato, sulcis intermedins un- 

 datis, elytris postice vix dilatatis, striis profunde punctatis, interstitiis convexis, 

 subtilissime parce punctulatis, testaceis fusco-maculatis. Long. -10 '15. 



Say, Journ. Acad. Nat. Sc/3, 200. 



Abundant in the Middle States, at Lake Superior, and in Nebraska. The under 

 surface as usual is black, the oral organs, the feet and inflexed margin of the 

 prothorax are testaceous. Of the markings of the elytra, the most obvious are 

 an inverted V at the suture, and two small rounded spots each side, all behind 

 the middle. Sometimes the thorax is almost entirely brassy green, but the in- 

 flexed pan always retains a testaceous tint. The very small specimens are found 

 at Lake Superior, and are accompanied by others of the usual size. 



7. H. inquinatus, oblongus, capite thoraceque nigro-ceneis, granulatis, hoc 

 latitudine sesqui breviore, postice vix angustato, lateribus late rotundatis, angulis 

 posticis rectis, marginibus testaceis, sulcis intermediis undatis, elytris fusco- 

 restaceis, piceo-nebulosis, striis profundis grosse punctatis, interstitiis convexis, 

 sutura alternisque paulo altioribus. Long. *13. 



Mannerheim, Bull. Mosc. 1852, 343. 



Helophorus consimilis Mannb. ibid. 1853. 



Russian America, Baron Chaudoir; one specimen, from Eagle Harbor, Lake 

 Superior. Easily known by the deeper and more coarsely puuctured striae, and 

 the unequal elevation of the intermediate spaces of the elytra: the elevation of 

 the 7th interstice is greater towards the base. 



The specimen sent to me as H. consimilis only differs from the type in being 

 less dark. It may be doubted whether this is different from H. auricollis 

 Esch. (Entomographien, 43: Mannb. Bull. Mosc. 1843, 260) described from 

 Unalaschka. 



8. H. s caber, obscure niger, capite thoraceque confertim granulatis, hoc 

 inEequali latitudine sesqui breviore postice angustato, lateribus crenulatis antice 

 rotundatis, postice obliquis, angulis posticis fere rectis, sulcis minus profundis 

 intermediis undatis, elytris punctato-striatis, sutura elevata, pone basin oblique 

 valde impressis, interstitiis 3, 5 et 7mo tuberculis magnis ornatis. Long. -13. 



Le Conte, Agassiz' Lake Superior, 217. 



Very abundant at Lake Superior. The third interstice has four elevations, one 

 of which is at the base, the fifth has three, and the seventh has two besides the 

 humeral carina : there is also on the ninth interstice a small tubercle near the 

 tip. These tubercles are arranged so as to form oblique series, which are parallel 

 with the oblique impression behind the base of the elytra. This species is cer- 

 tainly allied to, if not identical with H. tuberculatus of Northern Europe, but I 

 have not had the opportunity of comparing specimens, nor can I find any de- 

 scription sufficiently precise to warrant their union. 



H. angustulus Mannerh. (Bull. Mosc. 1853) from Russian America, is 

 unknown to me. It seems allied to H. linearis Lee, but the anterior angles of 

 the thorax aie described as being very much produced and acuminate. 



Hydrochus Germ. 



1. H. scab rat us, minus elongatus, griseo-argenteus, thorace latitudine 

 baud longiore, postice subangustato, lateribus subsinuatis, disco parce punctato, 

 inrcquali, 5-foveato, fovea antica media maiore et profundiore, elytris striatim 

 punctatis, dorso planiusculis, oblique biimpressis, postice valde declivibus tu- 



