44 [April, 



elytris oblongo-ovalibus, apice sinuatis, leviter striatis, punctis tribus minutis 

 impressis, antennis pedibus, thoracis elytrorurnque margine rufo-brunneis. Long. 

 4* lin. lat. H lin." 



With regard to the value of the first word of this diagnosis, I will merely ob- 

 serve that it occurs also in Count Mannerheim's diagnosis of Anch. maeulicoUis 

 (1. c. 199,) which, however, I found at San Diego, in July, flying about in the 

 evening twilight in such numbers as to be a source of great annoyance. 



B c. 



The species of this group are moderately large, winged, and a pure shining 

 black color; the thorax is slightly cordiform, with the posterior angles rectan- 

 gular; the dorsal line and anterior transverse impression are deep ; the basal 

 impressions are large, moderately deep and finely punctulate; the lateral margin 

 is moderate and is strongly retlexed, and slightly diaphanous in a strong light. 

 The elytra are more than one half broader than the thorax, truncate at base, 

 slightly sinuate at the extremity ; they are somewhat flattened on the disc, and 

 declivous towards the margin ; the stria? are deep, and the third interstice has 

 three impressed punctures. 



I regret to be partly answerable for the confusion introduced among the 

 species of this group, by mistaking those which have been already described, 

 and incautiously admitting some which are not sufficiently distinct. Having 

 carefully re-examined the subject, I hope that the results, here arrived at, may 

 be found corrrct. 



10. P. d e c e ns, niger, subnitidus, alatus, thorace postice subangustato, late- 

 ribus postice vix sinuatis, angulis posticis non prominulis, impressionibus basali- 

 bus dilatatis punctulatis, elytris magis deplanatis, tripunctatis, striis profundis 

 obsolete punctulatis. Long. -5 *56. 



Lee. Agassiz' Lake Superior, 205. 



Feronia decentis Say, Trans. Am. Phil. Soc. 2, 53. 



Andiomenus gagates Dej. Sp. Gen. 3, 107. 



Andiomenus decentis Say, Trans. Am. Phil. Soc. 4, 421. 



Anchomenus coracinus Lee. Ann. Lye. 4, 220. (Descriptio nequam.) 



Middle and Southern States ; not common. The description last cited was 

 made from a badly preserved specimen, in which the wings had probably been 

 pulled off to enable the elytra to be brought together ; at least, on raising the 

 elytra, I find fragments of the wings still remaining. The distinctive characters 

 of the species are the larger size, the less distinct posterior angles of the thorax, 

 (which are almost obtuse and very slightly rounded,) and the less lustrous and 

 more flattened elytra. The .fine punctures of the striae are sometimes almost 

 invisible. Dejean mentions four elytral punctures ; the second one, however, is 

 abnormal. 



11. P. s i n u a t us, niger, nitidus, alatus, thorace latitudine subbreviore postice 

 subangustato. lateribus postice vix sinuatis (basi apice sublatiore) angulis posticis 

 vix prominulis, impressionibus basalibus dilatatis, punctulatis, elytris paulo con- 

 vexis, bipunctatis, striis modice profundis, punctulatis. Long. .4 5. 



? Audio menus sinuatus Dej. Sp. Gen. 3, 108. l.ec. Ann. Lye. 4, 220. 



Middle States and Lake Superior. I am somewhat doubtful whether this is 

 really Dejean's species. He says, in comparison, with the preceding, "le corselet 

 est a peu pres de la meme forme ; seulement les bords lateraux sont un peu 

 moins largement deprimes." This difference, if it exists, is by no means obvious. 

 The only satisfactory characters I can find are the smaller size, the more shining, 

 less depressed and less deeply striate elytra. 



a. Thorace postice magis angustato, lateribus postice subsinuatis, angulis pos- 

 ticis subprominulis. 



Anchomenus depressus Hald. Proc. Acad. Nat. Sc. 1, 299. Lee. Ann. Lye. 

 4, 221. 



Platynus depressus Lee. Agassiz* Lake Superior. 



Western States and Lake Superior. The difference in the form of the thorax 



