THE CANADIAN ENTOMOLOGIST. 209 



beneath, broad oblique mark on sides of pleura, confluent behind with a 

 large mark covering almost entirely the under surface, four anterior coxae 

 and trochanters, and broad band at tip of abdominal segments, all white ; 

 front unarmed ; antennas long, sub-robust at tip ; mesothorax very finely 

 and densely punctured, metathorax more coarsely so ; wings sub-hyaline 

 areolet open ; legs fulvous-yellow, posterior coxae with base beneath and 

 apex above black, posterior tarsi yellow, fuscous at extreme tips ; abdo- 

 men sub-fusiform, the base and apex shining, post-petiole gradually 

 dilated ; ovipositor about half the length of the abdomen. Length .35 

 inch. 



Hab.— Louisiana (Lewis,). 



Mesostenus promptus. — £. Black; anterior orbits broad on sides 

 of face, clypeus, mandibles except tips, palpi, spot on each side of pro- 

 thorax above, lateral carinae at base of scutellum, tegulae, four anterior 

 coxae and trochanters beneath, and posterior tarsi except base and apex, 

 white ; sometimes the middle of the face is more or less white ; antennae 

 entirely black, slender at tips ; front unarmed ; mesothorax shining, 

 sparsely punctured, the two longitudinal lines deeply impressed, the middle 

 lobe prominent ; metathorax with lateral carinae of posterior face sharply 

 defined, but without prominent tubercles or spines ; wings sub-hyaline, 

 areolet sub-quadrate, closed ; femora fulvo-ferruginous, four anterior tibiae 

 and tarsi yellow ; abdomen slender, sub-compressed at tip, fulvo-ferru- 

 ginous, the three or four apical segments black. Length .35 inch. 



Hab. — Canada (Pettit) ; Illinois (Lewis). 



Mesostenus americanus. — °.. Black, shining ; short line on upper 

 anterior orbits, palpi obscurely, annulus on antennae, interrupted beneath, 

 obscure line on each side of scutellum at base, and dot on tegulae, whit- 

 ish ; front unarmed ; mesothorax with well impressed lines ; metathorax 

 rather coarsely sculptured, with a smooth polished space on each side at 

 base, sides of posterior face with sharply defined carina, but without pro- 

 minent tubercles or spines ; wings sub-hyaline, areolet longitudinally sub- 

 quadrate, closed ; four anterior legs, except coxae and trochanters, and 

 posterior femora ferruginous, posterior tibiae and tarsi fuscous, joints 2-4 

 of the latter occasionally more or less pale ; abdomen narrow fusiform, 

 shining, impunctured, ferruginous, apical segments sometimes dusky, first 

 segment long, slender, apical third rather suddenly dilated and sub- 

 quadrate; ovipositor as long as the abdomen. Length .30-33 inch. 



