THE GK0UXT) BEETLES. 



135 



thorax, emarginate at base and obliquely subtruneate at tip, the 

 striae fine; intervals fiat, the third with four to six dorsal punctures. 

 Tarsal grooves indistinct. 



KEY TO SPECIES OF GROUP P. 



a. Thorax narrower behind, the side margins more widely reflexed to- 

 ward the base : antennae with joints 5 to 11, paler. 



233. RUFICORXTS. 



aa. Thorax elongate-oval, the side margins uniformly narrow. 



6. Antennae piceous ; size larger. 7-7.5 mm. 236. gemellus. 



t/b. Antennae brownish-yellow ; smaller. 5-6.5 mm. 



c. Thorax black. 234. pictpexxis. 



cc. Thorax brownish-yellow. 235. lutulextus. 



233 (831). Platynus euficoexis Lee. Agass. Lake Sup.. 1850, 205. 



Elongate, slender. Head and thorax black; elytra piceous. shining; 

 antennae and legs brownish-yellow. Thorax oval, distinctly longer than 

 wide, hind angles rounded: basal impressions broad, rather shallow. Ely- 

 tra! striae hue. not punctured: intervals fiat, the third with five or six 

 small dorsal punctures, the first three on the third stria, the others on the 

 second. Length 7-8 mm. 



Frequent along the margin of Tippecanoe Lake. Kosciusko 

 County ; Lake and Posey counties ; scarce. March 26-Oetober 21. 



*234 (834). Platyxus picipexxis Kirby. Faun. Bor. Amer.. IV. 1837, 25. 



Elongate, very slender. Head and thorax black: antennae, legs and 

 elytra brownish-yellow. Thorax oval, about as long as wide; margin nar- 

 row, hind angles rounded: basal impressions narrow, shallow. Elytra 

 elongate, elliptical, the striae of moderate depth, not punctured : intervals 

 nearly flat, the third with tour to six dorsal punctures. Length 6-7 mm. 



Lake. Vigo, Posey and Kosciusko counties ; frequent. January 

 1-October 17. Gregarious in winter. 



*235 (835). Platyxus luttjlentus Lee. Proc. Phil. Acad. Nat Sci.. VII. 

 1854. 51. 



Elongate, very slender. Head black ; remainder of body brownish-yel- 

 low, shining. Thorax more finely margined, basal impressions smaller and 

 less distinct, and elytral striae finer than in the preceding. Dorsal punc- 

 tures four, larger than in picipennis, the first two on third stria, the others 

 on second. Length 5.5-6.5 mm. 



Throughout the State: frequent. Hibernates. Sometimes at- 

 tracted by electric lights. January 21-Deeember 23. 



236 (833). Platyxus gemellus Lee. Bull. Brook. Eut. Soc. II. 1879, 54. 



Elongate, slender. Piceous; head and thorax often darker: epipleura. 

 legs and base of antenme dark reddish-brown. Thorax oval, one-third 

 longer than wide, side margins very narrow, hind angles obsolete: basal 



