AMERICAN COLEOPTERA. 147 



In addition to these characters it will be observed that all our species 

 of Pinacodera have well developed wings, in Cymindis the wings are 

 aborted or absent. 



Our species are distinguished as follows : 



Hind angles of thorax obtuse, not prominent. 



Elytral intervals slightly convex in their entire length. Thoracic margin 



narrow, scarcely translucent Iinil>;if;i Dej. 



Elytral intervals flat.' Thoracic margin broad and translucent. 



platicollis Say. 

 Hind angles of thorax distinct, slightly prominent. 



Margin of thorax broad, not wider at base than apex punctigera Lee. 



Margin of thorax very narrow in front, a little wider at base. 

 Intervals convex at base, flat posteriorly. Thorax distinctly broader than 



long semisulcata n. sp. 



Intervals convex in their entire extent. Thorax not broader than long. 



sulcipeiiuis n. sp. 

 In addition to the above number in our fauna Chaudoir has described 

 four from Mexico. 



P. limbata Dej. — Piceous, legs, antenna?, humeral spot and sides of elytra 

 paler. Head smooth, slightly wrinkled above the eyes. Thorax one-third wider 

 than long, sides moderately arcuate and somewhat narrowed to base, hind angles 

 very obtuse or rounded, margin rather broad, moderately reflexed and translucent, 

 disc moderately convex, median line finely impressed, surface nearly smooth. 

 Elytra oval slightly oblong, with fine moderately impressed and obsoletely punctu- 

 late stria?, the intervals slightly convex with a few fine punctures very sparsely 

 placed, dorsal punctures on the third interval near the third stria; color piceous, 

 with testaceous humeral spot which extends along the outer two marginal inter- 

 vals to apex. Body beneath piceo-testaceous, smooth. Length .32 — .40 inch ; 

 8—10 mm. 



Male. — Anterior tarsi with four joints dilated and biseriately lamellate beneath, 

 middle tarsi less dilated, similarly lamellate, anal segment with two punctures 

 each side. 



Female. — Tarsi slender. Anal segment as in male. 



This species is as a general rule smaller than platicollis, the thorax 

 with a broader and more translucent margin, and has the humeral 

 spot and side margin pale. The hind angle of the thorax is also 

 more rounded 



Chaudoir and LeConte mention varieties of this species without the 

 humeral spot but I have not met with such, the specimens in the collec- 

 tion of LeConte referred to fuscata Dej., (which Chaudoir unites with 

 limbata), seem plainly paler forms of platicollis. 

 Occurs from the Middle States southward. 



P. platicollis Say. — Piceous, antenna? and legs testaceous. Head with 

 a few wrinkles above the eyes and with the vertex very sparsely punetulate. 

 Thorax one-third broader than long very little narrowed behind, margin moderate, 

 not translucent, distinctly reflexed, bind angles distinct not rounded', disc slightly 



