AMERICAN PHILOSOPHICAL SOCIETY. TtTO 



Length under one fifth of a inch. 



Allied to A. I/nomrus nob., but the .scLTiin'iits nf tlic tt'r;:um 

 are not margined around by dusky ; on each i.s a dusky trian^dc, 

 much dilated on the posterior margin, so as nearly to reach the 

 lateral edge. 



O.M.VLII .M (Irav. 



1. (). MAROl.v.\TUM. — Piceou.s, punctured ; antennaj and feet 

 dull rufous. 



Inhabits upper Mi.'^.souri. 



Body oblong-oval, plceous, punctured ; he:i<l, punctures sparse, 

 obsolete at tip, with an indentation each side between the an- 

 tenna and a longitudinal impressed line each side at base ; an- 

 tennae rufous at base, red brown obscure at tip with cinereous 

 hair; palpi rufous; thorax transverse sulxjuadratc, punctures 

 not crowded; posterior edge obscurely piceous ; elytra longitudi- 

 nally quadrate, covering more than half of the. terguin, exterior 

 margin piceous towards the humerus; exterior liind angles 

 rounded, sutural ones acute ; almost to be traced into strijc ; feet 

 piceous, paler towards the tip ; tergum obscurely rufous on the 

 margin, and on the posterior margins of the segments. 



Length one-tenth of an inch. 



I obtained this insect when with !Major Long's expedition to 

 the Rocky Mountains; I think it occurred at Engineer Canton- 

 ment on the Missouri. [464] 



2. O. noTUNDlcOLLE. — Piccous, black ; thorax roun<led be- 

 hind, emarginate before. 



Inhabits Pennsjlvania. 



IJody with rather large, numerous and profound punctures ; 

 antennto piceous, brown, the three ba.sal joints, hibrum and palpi 

 honey-yellow ; thorax transverse oval, deeply emarginate bcfure, 

 equally punctured ; posterior angles rounded ; edges piceous ; 

 elytra equally punctured, long; terminal edge piceous; tergum 

 piceous, rather paler on the posterior margins of the segments; 

 feet dark honey-yellow; venter somewhat piceous. 



Length less than one-fifth of an inch. 



Taken on the wing at twilight, in October. 



[Belongs to Oliqihrnm YaT. — Lec] 

 1834.] 



