PTEROSTICHIN/E 367 



Prothorax much narrower at base than before the middle 6 



6 Body small, abbreviated, the elytra but little longer than the head 

 and prothorax, the striae not punctulate. Convex, deep black; 

 head two-thirds as wide as the prothorax, with prominent eyes; 

 prothorax slightly wider than long, the transverse impressions dis- 

 tinct; sides not so coarsely reflexed as usual, rounded anteriorly, 

 less so posteriorly, the angles very obtuse; linear fovese separated 

 by a longitudinal convexity; carina distinct, very close to the edge; 

 elytra evidently less than one-half longer than wide, a fourth wider 

 than the prothorax, rounded at the sides, with subobsolete pos- 

 terior sinus; striae rather coarse, deep, the intervals somewhat 

 strongly convex. Length (cf) 12.7 mm.; width 4.7 mm. New 

 York (Adirondack Mts.) vapida Csy. 



Body larger, more elongate, the elytra nearly one-half longer than the 

 head and prothorax, the striae minutely punctulate along the bot- 

 tom 7 



7 Body less stout, moderately large and convex, polished black; head 

 well developed, three-fifths as wide as the prothorax, with prom- 

 inent eyes and converging sulci; prothorax a fourth or fifth wider 

 than long; base more than three-fourths the maximum width; apex 

 rather deeply sinuate; sides coarsely reflexed, evenly rounded, a 

 little less so basally, the angles broadly obtuse and blunt; trans- 

 verse impressions very feeble; fovese deep and coarse, divided by a 

 longitudinal convexity not attaining the base, the concavity punc- 

 tate; carina short, not strong and not very far from the margin; 

 elytra two-thirds longer than wide, a fourth wider than the pro- 

 thorax; sides arcuate and well reflexed, the sinus not very long and 

 rather distinct; striae very deep, the intervals strongly convex. 

 Length (cf 9 ) 14.0-16.5 mm.; width 5.0-5.7 mm. New York and 

 Pennsylvania to Indiana. Abundant. [Pt. bisigillatus Harris and 

 rugicollis Hald.] stygica Say 



Body larger and broader, black, polished; head a little larger, the eyes 

 and sulci nearly similar; antennae similar in coloration but distinctly 

 longer, especially the third joint in both sexes; prothorax larger and 

 broader, fully a fourth wider than long, the base fully as wide as 

 the sinuate apex and four-fifths the maximum width; sides broadly 

 and deeply reflexed, especially basally; impressions feeble; deep 

 linear foveae separated by a broad subtriangular rugose convexity, 

 not attaining the base; elytra broader, only three-fifths longer than 

 wide, a fourth to fifth wider than the prothorax; sides arcuate, the 

 gutter deep, the sinus very broad and feeble; striae deep, the 

 marginal deeply impressed, nearer to the sides than to the eighth; 

 minute punctulation at the bottom of the striae sharply defined 

 and rather close-set; intervals strongly convex; metasterna, and the 

 abdomen latero-basally, usually more conspicuously punctate than 

 in stygica. Length (cf 9) 15.4-17.5 mm.; width 5.8-6.3 mm. In- 

 diana, Illinois, Iowa and Missouri. Six specimens. . . .ingens n. sp. 



Body smaller than in stygica and rather more anteriorly narrowed, deep 

 black, polished; head moderately large, with prominent eyes and 

 converging sulci; antennae nearly as in stygica; prothorax smaller, 



