CERAMBYCIDAE. 347 



Front coxae conical, protuberant, cavities angulated, closed behind, 

 separated by very narrow prosternura ; middle coxae open exter- 

 nally, episterna and epimera separate (Mecas, Oberea, Tetraopes), 

 or nearly connate (Tetrops, Amphionycha). Ventral segments 

 nearly equal in our genera, 5th more or less different in the sexes, 

 and usually somewhat longer in 9. Legs short, thighs not 

 clavate, middle tibiae simple, hind tarsi with 1st joint not elon- 

 gated, last joint rather long ; claws variable in position as above 

 stated, always appendiculate or cleft. 



The side pieces of the metathorax are narrower behind ; they 

 are rather wide (as in Saperdini) in the first group, but less 

 developed in the others. 



The genera seem to indicate several groups, but without study 

 of the foreign forms it is unnecessary to define them at present, 

 and I have included them in a single table. 



Episterua of metathorax wide ; 



Epipleurse indistinct ; ungues feebly toothed 0" cleft. MECAS. 



Epipleurse distinct ; ungues broadly appendiculate. OBEREA. 



Episterna of metathorax moderate ; 



Eyes broadly divided ; prothorax dilated on the sides ; 



Ungues broadly appendiculate. TETROPS. 



Ungues cleft. TETRAOPES. 



Eyes not divided ; ungues cleft. 



Antennae pilose, outer joints suddenly shorter. AMPHIONYCHA. 



The American species of Tetrops are referable to Phaea 

 Newman, which seems not sufficiently distinct from the European 

 genus to be retained in a natural classification. 



The species of Tetraopes are numerous and very similar, being 

 of a bright red color with small black spots on the prothorax and 

 elytra ; they live exclusively upon plants of the genus Asclepias. 



Tribe XVI. METIIIIM. 



This tribe contains the lowest organized of the Lamiidae; 

 undifferentiated forms, which exhibit strong relationships to Oeme 

 and its allies among the Cerambycidae. 



The body is elongate, the prothorax cylindrical, the elytra 

 shorter than the abdomen, separately rounded at tip, and the 

 wings are extended along the dorsurn of the abdomen, and very 

 imperfectly folded at tip. 



The eyes are sparsely pilose, very large, coarsely granulated, 



