ANALYTICAL TABLE. XXXI 11 



A. Metathorax not narrowed below, much exca- 



vated, with very sharp edges ; post-scutel 

 bituberculate ; abdomen quite deformed . 297 



B. Metathorax triangular, narrowed posteriorly, 



not so much excavated, with sharp supe- 

 rior ridges. Post-scutel not crested. Second 

 abdominal segment channelled and reflexed, 



scarcely swolleu 299 



Division Stenodynerus ....... 301 



Table to assist in the determination of the Stenodyneri 304 



I. Metathorax having its posterior plate superiorly 



terminated by two erect teeth, or by an erect 

 crest ........ 309 



A. Metathorax not prolonged beyond the post- 



scutel, but truncate at its apex, posteriorly 

 excavated, angulate on each side ; the supe- 

 rior edges of the posterior plate terminating 

 in two erect spines, which are separated from 

 the post-scutel by deep fissures . . . 309 



B. Metathorax truncate, excavated ; superiorly 



margined by an arcuate ridge, rather crenu- 

 late, separated on each side from post-scutel 

 by a fissure 310 



C. Form not very slender. Metathorax produced 



horizontally beyond the post-scutel ; then 

 vertically truncate; the post-scutel quite 

 enveloped by it posteriorly, not reaching up 

 to the edge of the posterior face of metathorax ; 

 the posterior face of metathorax superiorly 

 terminating in an erect crest, parted by a 

 fissure. Vertex in 9 having two pilose tu- 

 bercles 311 



II. Metathorax not forming erect spines or crests 



behind the post-scutel. Its superior face not 

 produced behind the post-scutel. This last 

 not posteriorly truncate, but angular. Post- 

 scutel generally yellow, scutel usually black 312 

 1. Body slender, cylindrical. Concavity of the 

 metathorax wide, sometimes rather dis- 

 tinctly limited. First abdominal segment 

 bell-shaped, rather elongate. widely rounded 

 anteriorly, sessile or subsessile. Thorax 

 rather elongate, vaulted, Btyboylindrioal . 312 



