296 COLEOPTERA OF NORTFI AMERICA. 



the tubei'culate prothorax and slender legs prevent such an asso- 

 ciation. The eyes embrace the base of the antennai rather less 

 than in the neighboring tribes. 



Tribe VIII.— CAI.LICHROMIJVI. 



With this tribe commences a series distinguished by the scu- 

 tellum being acute at tip, and the antennae carinate on the lower 

 edge, with the poriferous system arranged in a groove each side 

 of the carina. The eyes are always very finely granulated, and 

 deeply emarginated, embracing the base of the antenna;, with the 

 upi)er lobe tolerably wide. 



This tribe is further distinguished by the mandibles being long, 

 pyramidal, nearly straight, bent only at the tip, which is acute. 

 The outer lobe of the maxilla; is longer than the palpi, which are 

 cylindrical ; the labial palpi are much longer, feebly dilated, 

 truncate at tip; the mentum is flat, trapezoidal, and porrect, 

 gradually becoming coriaceous in front; the base of the maxillas 

 is very large and flat; the gular process for support of the mentum 

 is nearly wanting; the gense are long. The prothorax is con- 

 stricted before and behind, armed with a strong lateral spine. 

 Scutellum moderately large, triangular, acute ; mesonotum smooth, 

 with a narrow triangular stridulating surface ; elytra narrowed 

 from the humeri, which are prominent, rounded at lip. Pro- 

 sternum not tuberculate, rounded behind, coxre globose, cavities 

 not angulated externally, completely closed behind; mesosternum 

 parallel, emarginate behind, coxal cavities rounded, scarcely 

 angulated, closed by the epimera, which extend inwards further 

 than usual ; metathoracic episterna wider in front, with very 

 distinct posterior scent pores ; hind coxae rather prominent. 

 Ventral segments, the 1st longer, the others ecpial, tapering con- 

 siderably ; the 5th in ? longer than wide, snbtruncate ; in % 

 deeply and broadly emarginate, with the C.tli joint filling the 

 space, and rounded behind. T-egs slender, hind pair elongated, 

 tibia; compressed, feebly carinated, spurs usually not large, 1st 

 joint of hind tarsi nearly as long as the others united. 



The last joint of the antennae is simple in both sexes, but is 

 much longer in the % . 



Four species of Callichroma are found in the warmer parts of 

 the country; they exhale an agreeable musky odor, and, with 

 one exception, are of a beautiful blue or green color. 



