Plate I. 



1. Spiny Witch-Hazel Gall. lHorvmphi.'< spinoms.) 



2. Witch-Hazel Cone Gall. (Hormaphis hamarnelidi".) 



3 . Cottonwood Petiole Gall . ( Pemphigus populicaulis. ) 



4. Hickory Cone Gall. {Phylloxera cmyae-fallax.) 



5. Cockscomb Gall on Elm. ' {Colopha uimicola.) 



6. Basswood Mite Gall . {Eriophyea ahnormis.) 



