AMERICAN COLEOPTERA. 51 



A. 



Prothorax wider than long, but little rounded in front, and almost truncate; last 

 joint of maxillary palpi dilated, triangular, inner angle well defined 2. 



Prothorax quadrate, but little rounded in front, and almost truncate; last joint of 

 maxillary palpi elongate triangular, inner angle indistinct 3. 



2. — Dusky black, pruinose with gray pubescence ; mouth and side margins of 

 ventral segments testaceous ; head and elytra very densely punctured ; 

 prothorax twice as wide as long, coarsely punctured, testaceous with an 

 angulated piceous transverse spot ; impressed dorsal line distinct. . Length 



8— 9 mm.; X. Y.; Tex 1. dentiger Lee. 



■ a. — Side margin of elytra pale. 



3. — Black, prothorax nearly smooth, narrowed in front, sides straight, margined, 

 excavated about the middle, fulvous, with a dorsal black stripe ; head densely 

 finely punctured. 9 , prothorax wider and less excavated at the sides than 



in %. Length 5— 5.5 mm. ; N. Y. ; 111.; Fla 2. e.lLCavatus Lee. 



a. — Side margin of elytra pale; tibire and tarsi sometimes testaceous; 



jnarginellus Lee. 

 /?. — Prothorax yellow, without dorsal stripe. 

 Prothorax slightly broader than long, yellow, with narrow di>rsal black stripe, 

 sides straight, more finely margined, only slightly explanate in front of the 

 middle; head opake, prothorax alutaceous; black, base of antenna?, palpi 



and part of legs testaceous; ?. Length 4 mm.; N. Y 3. vilis Lee. 



• Head opake, finely punctured ; black, anterior half of head, mouth organs, 

 base of antenna; and legs yellow; prothorax a little wider tlian long, sides 

 nearly straight, narrowly margined, more strongly in front of middle, 

 sparsely finely punctulate, yellow, with a narrow black dorsal stripe; 9. 



111.; one specimen, (Bolter) 4. l>ll««io n. sj). 



Head shining, sparsely ininctulate ; prothorax % as in exc.avatus ; side margin of 

 elytra, front half of head, base of antennre and legs yellow ; 9 . Prothorax a 

 little wider than long, less excavated at the sides, and not imjiressed behind 

 the iniddle. Length 5-5.5 mm.; 111., (B. D. Walsh). ..5. WalKhii n. sp. 

 Black, mandibles and base of antennre usually pale, tibiffi and tarsi tinged witli 

 testaceous, head punctnlatc, prothorax smooth, a little wider than long. 

 Length 5-5.5 mm.: L. Sup.: Col.: Cal. : Alaska R. fpaxiili Say. 



B. 



Moderate sized or small species, prothorax not elongate -• 



Small species, prothorax longer than wide - '• 



Larger, black, prothorax pale, broader than long, shining, witli a large black, 

 discoidal spot; head sparsely punctulale, shining, anterior half and under 

 side of first three antenna! joints pale; palpi piceous, last joint dilated, 

 strongly triangular: tarsi br<.ad : % tarsi broader than in 9. Length 



9— 10 mm.; Can.; L. Su^j. ; 111.; Penna 7. caroIinHS Fahr. 



«.— The black parts are brown,. /ac^aiws Say; Ks. 



2.— Elytra more finely or sparsely rugose-jwnctured •^• 



Elytra more coarsely and densely rugose-punctured ; black, prothorax yellow 

 "with a wide dorsal stripe black, wider than long, side margin strongly 

 reflexed, equally wide for tlie whole length; mouth sometimes piceo- 

 testaceous. Lengtli .^.5— 6 mm.; Atlantic region; Can.; Tex.; Fla.; N. Y. 



8. liiieola Fabr. 

 a. — Black stripe of prothorax wider, angulated at the ^ides: avgulatus Say. 



