OP PHILADELPHIA. 139 



States. I have found it in Pennsylvania and near the Rocky 

 Mountains. It is readily distinguished from our other species of 

 the genus by the bidentate anterior edge of the clypeus and 

 striate elytra. 



7. A. FEMORALis. — Blackish ; margins of the elytra and of 

 the thorax pale. 



Inhabits Missouri. 



Clypeus blackish-brown, minutely punctured, anteriorly emar- 

 ginate : thorax with small punctures, which are rather more nu- 

 merous each side ; lateral margins dull yellowish-white, with a 

 dusky dot : scutel black : elytra profoundly striated ; striae dilated 

 and transversely punctured ; interstitial spaces convex, narrow ; 

 color dirty yellowish-white, with a dusky, common disk : beneath 

 dark pieeous : thighs pale, yellowish-white. 



Length less than one-fifth of an inch. [216] 



Var. a. Pale margin of the thorax narrow and destitute of the 

 dusky spot. 



Found in considerable numbers on human excrement, at the 

 Pawnee villages. 



[Continuation, pp. 238—282.] 



TROX Fab. 



1. T. CAPiLLARis. — Clypeus rounded at tip, not reflected, ely- 

 tra tuberculated. 



Inhabits Upper Missouri. 



Body cinereous-fuscous : clypeus with two elevated, obtuse 

 tubercles ; tip rounded ; edge not reflected : thorax inequal, 

 canaliculate, minutely hispid ; posterior angles acute : scutel not 

 contracted at base or middle : elytra with elevated, subacute, re- 

 flected tubercles placed in regular series, which are alternately 

 smaller and separated by elevated capillary lines : punctures ob- 

 solete : beneath black : anterior .tibia two-toothed, the terminal 

 one emarginated. 



Length seven-twentieths of an inch. 



The clypeus of this insect is not angulated, nor reflected be- 

 1824.] 



