INSECT-GALLS OF THE VICINITY OF NEW YORK CITY 15 



25. White Oak Club Gall {Andricus clavula Bass.). — Club-shaped, hard and 

 •n-oody, with a few leaves growing from it. Length 5 to i in. Green in summer; 

 brown in winter. On tips of twigs of white oak {Qitcrcus alba). Very common. 



26. Succulent Oak Gall {Andricus palttstris Osten Sacken). — Globular, 

 green, succulent. Hollow inside, with a small seed-like kernel which rolls 

 about freely. Diameter about i in. On buds and young leaves of pin oak 

 {Qiicrcus paliistris). May. 



27. Small Oak Apple {Andricus singularis Bass.). — Globular, smooth, 



