60 W. H. ASHMEAD. 



The North American Cymphlse may be divided into five sub-fiimi- 

 lies of nearly equal value, distinguished by characters given in the 

 following table : 



Synoptic Table of the Sub-families. 



Section I.— GYMNOGASTRI Ashmead. 



* Radial area long and narrow. 



A. — Radial area closed ; abdomen cultTiform, segments about equal ; venter 



visible Sub-family I, IbaliinjE. 



AA. — Radial area seldom closed ; second abdominal segment occupying half, or but 

 little more than half the whole surface of abdomen ; venter visible. 



Sub-family II, Cynipin^. 

 AAA. — Radial area seldom open ; second abdominal segment occupying the whole 

 or nearly the whole surface ; venter not visible its whole length. 



Sub-family III, Inquilin^. 



Section II.— CRYPTOGASTRI Ashmead. 



** Radial area an equilateral triangle. 



B. — Abdomen short, globose, or semi-globose ; second abdominal segment longer 

 than the others ; scutellum round, convex. 



Sub-family IV, Allotriin^. 



BB. — Abdomen elongate ovate, compressed, with apex more or less pointed ; 

 third alidominal segment the largest ; scutellum quadrate, cupuliform 

 or spined Sub-family V, FiGlTlN^. 



Section I.— GYMNOGASTRI Ashmead. 



Sub-family I. — Ibaliin.e. 



This group contains one genus, easily recognized bv the following- 

 characters : 



Abdomen cultriform with all the segments about equal, fifth segment in 9 

 being much larger than in % ; wings with the veins more strongly devel- 

 oped than in any other of the Cynipidous groups ; radial area very long, 

 narrow and closed ; antennae filiform, 9 13, % 15-jointed. 



(1) Ibalia Latreille. 



Sub-family II — CH'nipin^t:. 



To this grou]) belong the true gall makers ; they produce galls or 

 abnormal deformations and excrescences on various trees and plants ; 

 the oak-rose and bramble being particularly subject to their attacks. 



It is by far the largest and best known of the different groups, 

 nearly one hundred species having already been described in the 

 North American fauna, which rei)resent thirteen genera. 



The genera may be separated with the aid of the following table : 



