80 GEORGE H. HORN, M. D. 



baise of the second (really the third) joint of the antennoe, and extend- 

 ing forward, usually concealed in the deep cavity on 

 the upper surface of the joint. This appendage re- 

 'senibles an elongate inner maxillary lobe, is slender 

 and furnished at tip with a brush of stiff curved 

 hairs. "When this appendage is raised so as to be- 

 come d'stinctly visible the entire joint resembles somewhat the large 

 mandible of a crustacean. All the species exhibit this appendage 

 varyin"- in size and development according to the species. I find no 

 mention of this in any authors who have written on this subject. Its 

 use is probably for grasping the antennae of the female in copulation. 

 In capturing these insects during the act, I have found the male hold- 

 ino- the female rather tightly by the antennae, but without any exam- 

 ination inferred that this was done rather by the bending of the outer 

 joints backward upon the second. 



Our species may be arranged in the following manner : 

 Elytra unicolorous. 

 Thorax yellow or reddish -yellow, iramaculate. 



Elytra very densely punctured ; abdomen rufous. .tricolor (Say). 

 Elytra less densely but more coarsely punctured ; 



abdomen black punotatus, Lee. 



Thorax with discal black spot of greater or less ex- 

 tent; sometimes entirely black. 

 Elytra finely and densely punctured, surface 

 more densely pubescent. • 



, ^ . 1 e f eximius, Er. 



Abdomen and anterior legs rufous | marginicollis, Lee. 



Abdomen and legs black nigriceps, (Say) 



Elytra more sparsely and coarsely punctured, 

 surface sparsely hairy j thorax almost en- 

 tirely black, shining cribrosus, Lee. 



Thorax rufous with two elongate, oblique black 



spots bipunctatus (Say). 



Elytra with entire limb and suture rufous. 



Elytra with apical and basal spot blue or bluish 

 black. 



Thorax rufous with two oblique black spots validus, Horn. 



Thorax rufous, immaculate. 

 Abdomen and legs black. 



Thorax smooth scarcely punctured quadrimaoulatus, Fab. 



Thorax densely and finely jiunctured opaque. histrio, Er. 



Abdomen and legs red pulcliellus, Horn. 



Thorax with discal black spot. 



Elytra densely and coarsely punctured ; larger 



species balteatus, Lee. 



Elytra finely and sparsely punctured; small 



species insulatus, Lee. 



