No. 22.] HYMENOPTERA OF CONNECTICUT. 361 



CYNIPOIDEA.* 



To this superfamily belong parasitic, guest or inquilinous, and 

 gall-making species, which are seemingly intermediate between 

 the aculeates and the almost exclusively parasitic forms of the 

 order Hymenoptera. 



The gall-making forms are in the majority, and are responsible 

 for many of the abnormal growths that are to be seen on quite 

 a variety of plants, especially oak trees. They are, when in the 

 galls, attacked by birds, and by a host of parasitic insects 

 belonging to the next succeeding superfamily of this order and 

 possibly to even some others of the superfamilies of the Hymen- 

 optera, so that it has been the wonder of students of these insects 

 that any of them should survive to perpetuate their kind. There 

 are many interesting aspects of the study of these mostly minute 

 insects, and any one wishing to pursue the subject intimately 

 will find an abundance of literature over which to browse. For 

 references to some of the more interesting papers on these insects 

 the reader may consult the bibliography given in the introduction 

 to this work on the Hymenoptera of Connecticut. 



Key to Families. 



1. Dorsal abdominal segments not extending down along the 



sides so as to meet beneath ventral segments, therefore 



all or nearly all of the ventral segments visible 2 



Dorsal abdominal segments extending down along the sides 

 and meeting beneath, thereby completely enclosing or con- 

 cealing the ventral segments or all of the ventral segments 

 except a part of the apical one or the hypopygium . . . 



FIGITID^ p. 363 



2. Basal joint of hind tarsi usually shorter and never much 



longer than joints two to five united; abdomen not at all 

 or very little longer than head and thorax combined 



CYNIPID^ p. 368 



*The classification here adopted is that of the late Dr. Wm. H. Ashmead. 



