4.8 ' , [February, 



ISARTHRUS. 



Antennae tenues, extus paulo incrassatae, articulis cylindricis, 2 12 subaequa- 

 libus, llmo paulo longiore. (Palpi invisi.) Thorax subtus ad marginem pro- 

 funde sulcatus : coxarum posticarum laminae tectrices intus naodice dilatatae, ad 

 apicem late rotundatae ; tarsi tenues, articulo Imo elongate, 2 4 gradatim bre- 

 vioribus, 4^ vix dilatato. 



This genus differs from Fornax, by the third joint of the antennae being not 

 larger than the 2d or 4th ; and by the posterior coxal plates being less dilated in- 

 teriorly, and much more broadly rounded at apex: the fourth tarsal joint is less 

 dilated. 



l.I. spretus, elongatus utrinque obtusus, ater, breviter cinereo-pubescens, 

 confertim subconfluenter punctatus, thorace convexo, antrorsum angustato, et 

 rotundato, elytris striis tenuibus, interstitiis rugose punclatis, subconvexis, an- 

 tennis pedibusque rufis. Long. '2. Lake Superior. This is the Fortiax spretics 

 of my catalogue in Agassiz' Lake Superior. 



EucNEMis Ahr. 

 a. Auien7ice serratce : tarsi artictilo 4'" simplici, 



1. E. clypeatus Say, Trans. Am. Phil. Soc. 6, 189: Elate?- clypeattis 

 Say, Ann. Lye. 1, 266. Pennsylvania, Zimmerman. 



b. AntenncB s err at a : tarsi articulo 4^ breviter lohato, 



2. E. amaenicornis Say, Trans. Am. Phil. Soc. 6,189. Southern and 

 Middle States. The antennae are subflabellate in both sexes : some specimens 

 have the thorax a little rounded on the sides : these are probably females : the 

 whole appearance is so similar to that of genuine Eucnemis, that I have not ven- 

 tured to establish a separate genus upon the slight difference in the antennae and 

 tarsi. 



MiCRORHAGUS Esch. 



1. M. i m p e r f e c t u s, elongatus, utrinque obtusus, ater pubescens, puncta- 

 tus, capite canaliculato, thorace latitudine breviore, lateribus antice rotundatis, 

 elytris tenuiter striatis,pedibus"ruio-piceis, sulcis pectoralibus postice indistinctis. 

 Long. '22. New York, one female. 



2. M. subsinuatus, elongatus vix cuneiformis. ater, supra obsolete pubes- 

 cens, punctatus, thorace brevi, antrorsum subangustato, lateribus subsinuatis, 

 angulis posticis explanatis, elytris rugose punctatis, obsolete striatis, tarsis tes- 

 taceis. Long. -2. Georgia, one male; similar to the next, but more than twice as 

 large, and easily distinguished by the sinuosity of the sides of the thorax : it is 

 also more coarsely punctured and less narrowed behind. 



3. M. triangularis. Elater triangtdaris Say, Journ. Ac. Nat. Sc. 3, 170 : 

 Eucnemis triangularis Say, Trans. Am. Phil. Soc. 6, 189. Southern and West- 

 ern States : the thorax is not at all narrowed in front ; the anterior angles are a 

 little rounded. It is singular that Guerin, (Ann. Ent. Soc. Fr. 1, 187,) should 

 refer this species to Eucnemis, when Say expressly states the antennal groove to 

 be near the middle of the pectus. 



4. M. h u me ral is. Eucnemis humeralis. Say, Trans. Am. Phil. Soc. 6, 

 J89. Pennsylvania, Dr. Melsheimer. 



Galba Esch. 



l.G. (Dcndrocharis) flavicornis Guerin. Ann. Ent. Soc. Fr. 2d ser. 

 1, 193. tab. 6, fig. 60, 61. Georgia; I have never seen this fine species. 



The following species are unknown to me, and the genera to which they be- 

 long doubtful. 



P^ucnemis quadricollis Say, Trans. Am. Phil. Soc. 6,186. Pro- 

 bably Melasis. 



Eucnemis frontosus Say, ibid. Probably not of this group. 



Eucnemis calceatus Say, ibid. The description of the antennae agree 

 perfectly with my Isarthrus spretus ; but the 4th Joint of the tarsi in that species 

 is not lobed beneath. 



