THE GROUND BEETLES. 127 



neatli old logs in dry. upland open woods. In two specimens the 

 intervals are much more coarsely punctured, more convex and 

 strongly alutaceous. 



*20S (784). PLATYNUS PUSILLUS Lee., Proc. Phil. Acad. Nat. Sci., VII. 

 1854, 39. 



Elongate, very slender. Head and thorax piceous, the elytra usually 

 reddish-brown; antennae and legs light brown. Thorax long and cordate; 

 base much narrowed, subcylindrical ; impressions elongate and narrow, 

 hind angles rectangular; median line deep, surface sparsely and rather 

 coarsely punctured. Elytra twice as wide as thorax, tips rounded, strife 

 deep and finely punctured. Length 6-7 mm. 



Throughout the State ; frequent. Hibernates. January 21- 

 September 11. 



GROUP D. 



A large group of winged species, usually black, the legs and an- 

 tenna? sometimes of the same hue, more often piceous or reddish- 

 brown. Thorax rounded, the margin usually slightly widened and 

 reflexed toward the base, hind angles very obtuse or altogether 

 rounded, basal impressions variable, either broad and shallow or 

 deep and narrow, sometimes almost obsolete. Elytra often not 

 much wider than thorax, humeri broadly rounded, the base trun- 

 cate or subemarginate, tips rounded and hardly sinuate; intervals 

 mostly flat, the third with three to seven punctures. Tarsi with 

 distinct lateral but no medial grooves. 



KEY TO SPECIES OF GROUP D. 



a. Thorax transversely oval or rounded, rarely subquadrate; elytra not 



deeply emarginate at base. 



6. Either black (rarely bronzed), or green with disk of elytra cu- 

 preous ; hind angles of thorax usually much rounded. 

 c. Dorsal punctures three. 

 d. Antennae, and usually the legs, wholly black or piceous. 



e. Thorax with side margins wider and strongly reflexed near 



the base. 



f. Elytral striae fine, the intervals flat. 

 p. Hind angles of thorax obtuse, rather distinct. 



211. MCERENS. 



ffff. Hind angles of thorax entirely rounded. 212. TENUIS. 

 ff. Elytral striae deep, the intervals more or less convex. 



7*. Elytral strife strongly punctured; hind angles entirely 

 rounded. 213. COLIARIS. 



hh. Elytral striae not or feebly punctulate. 



'. Hind angles of thorax entirely rounded; elytral inter- 

 vals distinctly convex. 214. ATRATUS. 

 [923402] 



