458 WILLIAM G. DIETZ, M.D. 



The following genera are indicated : 



Third tarsal joint bilobed, fourth joint shorter than the two preceding joints 

 combined. 

 Second veiiti-al segment as long as the following two segments together, third 

 segment narrowed on the sides, not widely attaining the lateral mar- 

 gin ; anterior coxie more widely separated, fully one-half the distance 

 of the middle coxse. 

 Very robust form, lateral tubercles of prothorax very distinct, third tarsal 



joint broadly bilobed Perigaster. 



More elongate, thoracic tubercles almost obsolete, third tarsal joint scarcely 



bilobed Pareiithis. 



Second ventral segment longer than the two following segments, third not nar- 

 rowed on the sides, fully attaining the lateral margin ; anterior coxse 

 narrowly separated, scarcely more than one-third the distance of the 

 middle coxse (except Rhinoncus). 



Prosternum without ante-coxal ridges Peleiiomiis. 



Prosternum with ante-coxal ridges. 



Eyes with distinct supra-orbital ridges, anterior coxie separated one-third 



the distance of the middle coxse Iflecopeltus. 



Eyes without supra-orbital ridges, anterior coxse. separated one-half the 



distance of the middle coxa? Rliinoucus. 



Third joint of tarsi narrow, fourth as long as the preceding joints. PI. xi v, tig. 40. 



Pliytobius. 



PERIGASTER gen. nov. 



Under this generic name I have separated the two species described 

 by Dr. LeConte under Ccelogaster, and is thus characterized : Beak 

 stout, shorter than the prothorax, widened towards the apex, scrobes 

 linear, oblique ; antennse inserted one-third (%), or two-fifths ( 9 ) with 

 6-jointed funicle, joints 1-3 longer. Eyes large, round, moderately 

 convex, partially concealed in repose, with acutely elevated orbital 

 margin ; prothorax strongly narrowed in front, ocular lobes obsolete, 

 apical margin bicuspid, lateral tubercles present, basal margin nearly 

 straight each side ; scutel very small. Elytra wider at the base than 

 the prothorax, broadly oval ; pygidium nearly perpendicular ; pro- 

 sternum rather short and deeply emarginate in front of the coxa?, 

 not canaliculate, mesosternum short, feebly emarginate in front, 

 truncate behind and forming less than one-half of the middle coxal 

 cavities; motasternum long, entering well between the middle coxa3 ; 

 second abdominal segment shorter than the two following segments 

 together, the third nai-rowed on the sides ; anterior coxjc conical, 

 prominent, rather widely separated, middle coxie small, globular, 

 separated twice the distance of the anterior coxai and less than half 

 the distance of the posterior. Legs slender, femora nnitic, scarcely 



