THOS. L. CASEY. 



exact position pointetl out ; or, in other words, when he is told where 

 to look for it. These differences relate more particularly to the shape 

 and relative size of the head, pronotum, and elytra, as well as to 

 minor characters of the under surface. 

 Philadelphia, Jcxe 23, 1884. 



PTEROSTICHrS. 



P. zepliyrus n. sp. — Form rather slender. Upper surface piceous- 

 black, elytra somewhat paler, iiuder surface dark fuscous, legs same, poste- 

 rior edges of the ventral segments very pale testaceous. Head moderate, as 

 long as width across the eyes ; epistoma broadly, evenly, aud feebly eraargi- 

 iiate anteriorly ; labrum slightly more than twice as wide as long, almost 

 transversely truncate anteriorly, angles acute ; eyes flat, oval, nearly entirely 

 visible from above, very near the posterior angles ; posterior supra-orbital seta 

 slightly behind the eye ; antennae as long as the head and prothorax together, 

 dark rnfo-testaceous, paler toward tip, second joint scarcely one-half as long 

 as the third ; mentum tooth rather small, deeply and triangularly incised at 

 tip, and deeply excavated on the exposed surface ; third joint of labial palpi 

 slightly shorter than the second ; between the gular sutures there is a short, 

 narrow, regularly impressed line. Prothorax as broad as long, rather 

 strongly constricted behind ; disk strongly depressed ; median line distinctly 

 visible throughout, lateral basal depressions very well marked ; surface 

 highly polished throughout ; sides strongly arcuate anteriorly and sinuate 

 posteriorly ; anterior angles somewhat acute, posterior acute and projecting; 

 base broadly and somewhat angularly emargiuate. Scutellum small and 

 triangular. Elytra at base as wide as the prothorax, very slightly more 

 than twice as long as the latter, widest at two-thirds the length posteriorly ; 

 sides rather strongly arcuate ; disk moderately convex, striae deeply im- 

 pressed, interspaces rather strongly convex. Last ventral segment strongly 

 carinated in the middle toward the apex. Anterior tibiae rufous toward the 

 tip. Length 12.0 mm. 



The exact locality of this species is not known ; the single repre- 

 sentative, which is in my cabinet, is a male, and was probably col- 

 lected in the extreme Southwest. 



The very marked and narrow cariniform elevation of the last 

 ventral segment renders it easily recognizable. 



P. oscillaiis n. sp. — Form slender. Surface above black, beneath deep 

 piceous-bhick, legs slightly paler toward the tips of the tarsi. Head moderate, 

 longer than width across the eyes ; labrum slightly more than twice as wide 

 as long, sides nearly straight, broadly and very feebly emargiuate anteriorly', 

 angles slightly rounded ; eyes situated very near the posterior angles, rather 

 convex ; posterior supra-orbital seta on a line with the posterior edge of the 

 eye ; antennae as long as the head and prothorax together, dark fuscous, 

 paler toward the tip, pubescence fulvo-testaceous, second joint more than 



