THE CANADIAN ENTOMOLOGIST. 209 



First joint of maxillary palpi not much swollen and much shorter than 

 the following joints united ; last joint of the labial palpi not 

 especially small; <$ antennae enrolled at apex. . Micragris, Saussure. 



(Type M. spinotae, Sauss.) 



7. Clypeus not transverse, as long or longer than wide 8. 



Clypeus transverse, wider than long ; labial palpi and paraglossae very 



slender Leptochilus, Saussure. 



(Type Pterochilus mauritianus. Lepel.) 



8. Last three joints of maxillary palpi normal, not very small ; labial 



palpi and paraglossia not especially slender 9. 



Last three joints of maxillary palpi very small. . Rhynchium, Spinola. 



(Type Vespa oculata, Fabr.) 



9. Mesonotum without distinct parapsidal furrows, either wanting or 



only vaguely defined basally ; <$ antennae at apex ending in a hook 



or spirally contorted ' °- 



Mesonotum with usually distinct parapsidal furrows ; S antennae at 



apex simple Odynerus, Latreille. 



(Type Vespa murarius, Latr.) 



10. Thorax coriaceous or closely finely punctate ; clypeus at apex usually 



semicircularly emarginate, bidentate ; antennae widely separated at 

 base, in g at apex depressed and spirally contorted ; mandibles 2- 



to 3-dentate Hoplomerus, Westwood. 



(Type Vespa spinipes, L.) 



Thorax punctate, not coriaceous ; clypeus at apex truncate or 



subemarginate; antennae not widely separated at base, in £ ending 



in a hook ; first abdominal segment dorsally at apex with a short 



median groove ; second ventral segment produced and truncate at 



base ; mandibles 4-dentate Leionotus, Saussure. 



(Type Odynerus humeralis, Hal.) 



11. First abdominal segment truncate at base, not divided by a longi- 



tudinal groove or furrow ; antennae in <£ ending in a hook. 



Maxillary palpi 6-jointed Ancistrocerus, Westwood. 



(Type Vespa parietum, Linne.) 



Maxillary palpi 5 -jointed Monobiella, Ashmead, gen. nov. 



(Type Vespa atrata, Fabr.) 

 First abdominal segment somewhat funnel-shaped, and divided above 

 by a deep longitudinal groove ; antennae in $ 



simple Symmorphus, Wesmael. 



(Type Vespa sinuata, Fabr.) 



