328 THE CANADIAN ENTOMOLOGIST. 



28. Thorax quadrangular, not much narrowed posteriorly, the sides 



parallel or nearly, sometimes laterally slightly sinuate or compressed 



medially, rarely obtrapezoidal 29. 



Thorax quite differently shaped, most frequently obpyriform, obovoid, 

 violin-shaped or otherwise, usually narrowed posteriorly or much 

 contracted at the sides 39. 



29. Pygidium not perfectly smooth, usually striate^ rugulose, coriaceous 



or punctate, and with a pygidial area, i.e. with an elevated rim at 



the sides 30. 



Pygidium usually smooth, without a distinct pygidial area, or the 

 elevated rim is wanting or exceeding delicate 44. 



30. Thorax with the front angles rounded, 7iot acute •31. 



Thorax with the front angles acute ZZ- 



31. Lateral margins of the thorax and the upper margin of the 



metathoracic truncature dentate or denticulate 32. 



Lateral margins of the thorax and the upper margin of the meta- 

 thoracic truncature usually simple, not dentate at the most, and 

 rarely with only the upper margin of the truncature dentate .... 34. 



32. Thorax with sides parallel or nearly; head subquadrate, without 



tubercles between the antennae ; mandibles simple, unarmed ; first 

 joint of the flagellum obconical, about twice as long as thick, the 



second joint transverse. (Africa) (?) Trogaspidia, Ashmead. 



Thorax with side slightly compressed medially ; head large, quadrate, 

 with two tubercles between the antennae ; mandibles very long, 

 tridentate (two widely-separated teeth within on inner margin) ; 

 first joint of the flagellum very long, longer than 2 and 3 united. 



(South America.) Euspinolia, Ashm., gen. nov. 



(Type Mutilla chilensis, Spin.) 



33. Head quadrate, a litde wider than the thorax, with two triangular 



tubercles between the antennae (Africa.) . Blakeius, Ashm., gen. nov. 



(Type Mutilla bituberculata. Smith.) 



Head transverse, not wider than the thorax, without tubercles 



between the antennae. (Asia.) . . Radoszkowskius, Ashm., gen. nov. 



(Type Mutilla simplicifascia, Radoszk.) 



34. Upper margin of the metathoracic truncature armed with three or 



more teeth 3.S • 



Upper margin of the metathoracic truncature normal, unarmed. . .36. 



