AMEaiCAN OLEOPTERA. 297 



In the proof sheet one entire line of MSS., was omitted and also all the in- 

 terlined emendations. 



Page 120 lines 7 and 8, omit striw and all the words after it. A longer series 

 shows this character to be fallacious. 

 Page 12(5 line 9 from bottom for testoceous read testaceous. 



" 127 " 14 omit distinctly, 



" 128 " 17 after ferruginous add, Head smooth, clypeus feebly emargin- 

 ate at middle. 

 Page 130 last line, omit at base. 



" 131 next to last line omit by and add a comma, 



" 131 last line read comparatively and omit comma. 



" 132 line 10 for wiihin read within. 



" 133 " 15 for margined read marginal. 



Bemarks on the Species of the Gsnus ISOM/ILTJS £r. of the United States. 

 BY GEO. H. HORN, M. D. 



In a pamphlet entitled " Notices Eiitomologiques." Mr. Albert 

 Fauvel iu an article entitled " Etudes sur les staphylinides de I'Ameri- 

 que Centrale, principalement de Mexique," publishes an account of 

 the species of homalas, of that region. As our own species are rather 

 rare and it being impossible for nie to furnish him with the necessary 

 material for his systematic catalogue of the Staphylinidaj in general, 

 I have thought it proper to review our four species and point out 

 some variations exhibited by them from the present descriptions of the 

 genus. 



In the work above cited Fauvel makes the following remarks : "The 

 species of Isomnlus are remarkable for their extremely flattened form, 

 indicating a priori their habit of living under bark and in the trunks 

 of decayed trees. They are distinguished from the other Piestini by 

 the following characters; body glabrous, smooth; head with lateral 

 longitudinal groove; front mutic ; mandibles prominent mutic ; max- 

 illary palpi with last joint somewhat shorter than the preceding; 

 thorax not grooved, broadly sinuate behind; elytra without sutural 

 stria;; legs mutic; abdomen strongly margined." 



Our species all agree in being very much depressed, smooth and 

 shining; thorax strongly narrowed at base and not longer than the 

 head. 



Two have a distinct sutural stria nigrellus, Lee. and canadensis, n. sp. 



Two have no sutural stria .pallidus, Lee. and fasciatus, Lee. 



By means of the groove at the side of the head they may be tabu- 

 lated in the following manner ; 



Lateral groove above the eyes and extending slightly behind 



