lOG THE CANADIAN ENTOMOLOGIST. 



from the middle which is iiigulose ; pygidium oblong-oval, nigulose 

 towards base ; mandibles with a sinus before apex, appearing 



bidentate Anodontyra, Westwood. 



39- Clypeus wiihout a trace of a median carina, the anterior margin 



truncate  • 40. 



Clypeus with a. more or less distinct median carina, the anterior 

 margin subangularly produced. 



Pygidium oblong-oval, longitudinally striate, and with a -lobe or 

 tooth on each side before the apex; first abdominal segment 

 with traces of transverse carina or elevated lines at apex, the 

 second segment with many transverse folds or carina^, 1 7 or 

 more ; metathorax sloping from its 

 base Myrmecodes, Latreille (partim). 



40. Pygidium oblong, with a more or less elongate, lanceolate elevation 



on its disk gradually broadened posteriorly, the elevation with 

 some longitudinal lines towards base, smooth at apex ; first 

 abdominal segment with a depression at apex, the second segment 

 with live transverse folds or carina^, metathorax sloping from a little 

 beyond its base, leaving a short but distinct 

 metanotum Thynnoides, Guerin. 



41. l^ygidium very narrow, or strongly compressed towards base, with an 



elevation towards apex 42. 



Pygidium neither very narrow nor compressed towards base, without 

 an elevation or disk, above flat or subconvex, striate, punctate or 

 rugulose 45. 



42. Head about twice as wide as thick antero-posteriorly, or three times as 



wide as thick when viewed from above. 



Second dorsal abdominal segment with three or more transverse 



folds or carin^e 43. 



Second dorsal segment with only oiie transverse carina just before 



apex, the anteriorly portion rudely 



punctate Psammothynnus. Ashm., gen. nov. 



43. Second abdominal segment \y'\\\\7nany transverse folds orcarinse. .44. 

 Second abdominal segment with three transverse folds or carinae. 



Pygidium elongate, smooth, the hypopygium with two converging 



carinae at base Zelaboria, Saussure. 



(Type Thynnus carinatus. Smith.) 



44. Second abdominal segment with 20 or more transverse carinse, the 



first segment with a transverse furrow just before apex, the third and 



