THE CANADIAN ENTOMOLOGIST. 87 



Tibise not carinated, form usually stouter. Elytra in most cases 

 with lighter coloured angulated cross-bands ; antennae usually 

 shorter than the body in both sexes. Punctuation fine 28. 



28. Head comparatively small, front short, oblique ; legs hardly clubbed. 



Intercoxal process of first ventral rounded 29. 



Head large, front long, intercoxal process acute 32. 



29. Prothorax transversely excavated at sides near the base, prosternum 



perpendicular at tip Cyllene. 



Prothorax not excavated at sides, which are rounded and constricted 

 at base. Prosternum declivous at tip 30. 



30. Antennge filiform 31. 



Antennae subserrate, compressed. Size large, colours strikingly con- 

 trasted with black and yellow bands Flagio?iotus. 



31. Large species, prothorax entirely black, much rounded on the 



sides Calloides. 



Smaller, less robust ; prothorax with central black spot, the re- 

 mainder clothed with gray pubescence, sides much less 

 rounded Arhopalus. 



32. Elytra plane ; moderate sized species 33. 



Elytra gibbous at base ; small ant-like species 35. 



33. Head with a carina of variable form Xylotrechus. 



Head not carinated 34. 



34. Prothorax with transverse dorsal rugse or ridges Plagit/wiysus. 



Prothorax without transverse ridges Clytanthus. 



35. Elytra with a transversely oblique ivory-like band Euderces. 



Elytra without ivory band Cyrtophorus. 



36. Second joint of antennas equal to the fourth Microclytus. 



Second joint of antenna? less than half as long as the fourth . . Atimia. 



37. Elytra short, not covering the wings Necydalis. 



Elytra normal 38. 



38. Joints 3 to 5 of antennge much thickened at their tips, inner angle 



sometimes much produced. Large insects, bright blue with an 



orange band across base of wing-covers Desmocerus. 



Joints 3 to 5 of antenna? normal, usually slender and never produced 

 inwardly at tips. Elytra usually tapering to apex, sometimes more 

 or less dehiscent 39. 



39. Spurs of hind tibite terminal .• 40. 



Spurs of hind tibia' not terminal, but borne at the base of a deep 

 excavation. Tliorax tuberculate or spinose at sides Toxotus. 



