468 REVISION OF the elaterida: 



Middle States. Diners from the preceding in the thorax not being channelled behind, 

 and in the punctuation becoming finer near the base; also in the elytra being slightly nar- 

 rowed from the base, and less obtuse at the apex, and in the interstices being less densely 

 punctured. The antennsB are a little shorter than the thorax and strongly serrate. 



20. E. nigricans, ater, helvo-pubescens, thorace punctato, postice canaliculato, elytris acutius- 

 culis, striis punctatis, interstitiis remote rugose punctatis, antennis piceis articulis 2 et 3 subffiqualibus, 

 pedibus ferrugineis. Long. "31. 



Ampedus nigricans Germ. Zeitschr. 5, 17G. 



Mater testaceipes Mels. Proc. Acad. Nat. Sc. 2, 213. 



Pennsylvania and New York. Diners from E. molest us by its less obtuse elytra, 

 and from E. fuscatus by the punctuation of the thorax not being fine at the base, and by 

 the dorsal channel being distinct posteriorly. In the specimens seen, the thorax is nar- 

 rowed anteriorly from the middle, and is a little longer than wide ; Germar describes the 

 thorax as being "latitudine baseos subbrevior;" but this difference may be sexual. 



21. E. ursulus, ater, nigro-pubescens, thorace punctato, postice subcanaliculato, elytris postice 

 obtusioribus, striis punctatis, interstitiis rugose punctatis, antennis articulo 3'° secundo paulo longiore, 

 pedibus rufo-piceis, vel nigro-piceis. Long. "81. 



Melsheimer, Proc. Acad. Nat. Sc. 2, 213. 



Pennsylvania and New York. This species is readily distinguished from the preceding 

 closely allied species by its pubescence being finer, and so dark coloured as to be almost 

 invisible, unless viewed laterally; the thorax is a little longer than wide, and is narrowed 

 almost from the base and rounded on the sides. 



This species seems subject to variations: in the type the interstices of the elytra are 

 sparsely punctured, and the feet dark rufo-piceous; in two other specimens the feet are 

 black, and the elytra more densely rugous. I should have considered the type as Ampe- 

 dus pedal is Germ. (Zeitschr. 5, 176,) but the thorax is not densely punctured, as re- 

 quired by his description. 



22. E. lacustris, ater, griseo-pubescens, thorace punctato, antrorsum angustato, elytris basi late 

 ferrugineis, striis punctatis, interstitiis subconvexis, disperse punctatis, antennis pedibusque tcstaceis, 

 illis articulis 2 et 3 subscqualibus. Long. - 22. 



One specimen, Lake Superior. The thorax is narrowed from the middle to the apex, 

 and broadly rounded on the sides; it is scarcely longer than wide, the elytra are parallel 

 anteriorly, obtusely rounded posteriorly; the antennas are not longer than the thorax, 

 which character would distinguish it from Ampedus pull us Germ. (Zeitschr. 5, 1G2.) 



23. E. fus cuius, ater, helvo-pubcsccns, thorace punctato, ante medium angustato, angulis posti- 

 cis tcstaceis, elytris subtilius striatis, striis punctatis, interstitiis planis confertim punctatis, testaceis, 

 sutura late infuscata, antennis pedibusque testaceo-fuscis, illis articulis 2 et 3 tequalibus. Long. -26. 



Lake Superior, two specimens. The diorax is not longer than wide, and tolerably 

 strongly rounded on the sides, which arc parallel behind the middle. The elytra arc pa- 

 rallel on the sides, and gradually somewhat obtusely rounded at the tip. The antenna? 

 arc as Ion" - as the thorax. 



