322 THE CANADIAN ENTOMOLOGIST. 



CLASSIFICATION OF THE ENTOMOPHILOUS WASPS, OR 

 THE SUPERFAMILY SPHEGOIDEA. 



BY WILLIAM H. ASHMEAD, ASSISTANT CURATOR, DIVISION OF INSECTS, 



U. S. NATIONAL MUSEUM. 



(Paper No. 6.) 



Family XXIII. — Nyssonida?. 



Anyone with the use of my table of families ought readily to recog- 

 nize any wasp falling in this family, and especially after reading my 

 remarks under the family Mellinidse. The only group that could possibly 

 cause trouble or confusion would be the subfamily Gorytince, which 

 closely resembles the Mellinidcp., but which may be easily separated from 

 the latter by paying close attention to the shape of the first abdominal 

 segment and examining the mesopleura for the mesosternal suture or 



carina 



The family Nyssonida:,' may be divided into four distinct groups, 

 which I have designated as subfiimilies, and which are easily distinguished 

 by the characters made use of in the following table : 



Table of Subfamilies. 

 Marginal cell always pointed at apex, never truncate, and without an 

 appendage; antennae inserted far above the clypeus, always away from 

 the clypeal suture. 



Front wings with the second cubital cell broadly sessile, never 

 triangular or petiolate, and receiving both recurrent nervures; 

 mesopleural furrow usually deeply and sharply defined, com- 

 plete Subfamily I., Gorytinte. 



Front wings with the second cubital cell petiolate, rarely triangular, 

 sessile ; mesopleural suture wanting or subobsolete, evanescent 

 posteriorly. 



Metathorax with the superior hind angles unarmed, rounded or 

 obtuse ; pronotum dorsally not short, subquadrate ; forms 



elongate Subfamily II., Alysonince. 



Metathorax with the superior hind angles always acute or pro- 

 duced into stout teetli or spines ; pronotum dorsally short, 

 narrowly transverse ; forms broad, 



robust Subfamily III., Nyssoninie. 



Marginal cell always broadly truncate at apex, with an appendage ; 

 antennae inserted close to the clypeus, or very close to the clypeal 

 suture Subfamily IV., Astatinas. 



