EXPLANATION OF PLATE. 



Fig. 1. Gall of Antistrophus silphii on Silphium integrifolium, 

 slightly enlarged. 



Fig. 2. Another gall of same species, with side cut away, show- 

 ing internal cavities; a, larval cells; natural size. 



Fig. 3. Galls of AntUtrophus lacimatns on Silphium lacinia- 

 tum, enlarged three diameters. 



Fig. 4. Galls of Aiitistrophus riifus and A. minor in Silphium 

 laciniatum, natural size. 



Fig. 5. Galls of Dryophanta lanata on Quercus, natural size; a- 

 denuded gall, enlarged five diameters. 



