HYMENOPTERA OAK GALLS. 161 



II. In Buds. 



Polythalamous ; very large, spongy, apple-like. In terminal buds, 

 or often on lateral buds on terminal shoots. May and June 



Teras terminalis. 



Monothalamous. In April and May, on trunks of old trees, gen- 

 erally near the ground, like a round drop of sealing-wax 



Trigonaspis megaptera. 



Like marbles on twigs or young trees in nursery ; green from July 

 to September, and light-brown throughout the winter ; either singly 

 or in clusters ...... Cynips Kollari. 



Spindle-shaped, with long peduncle. July and August 



Apliilotlirix callidoma. 



Ovoid, green, spotted, smooth, hard . Apliilotlirix albopunctata. 



Gall wholly enveloped in leaf-scales . Apliilotlirix ftcundatrix. 



Gall very thin, and to all appearance only an undeveloped bud. In 

 April and May ..... Spathegaster aprilinus. 



Globular, green, projecting from bud scales in September and Octo- 

 ber ....... Apliilotlirix globuli. 



Terminal twig inflated with a tuft of leaves, growing from the 

 inflated portion ...... Andricus inflator. 



Irregular swellings on twig .... Andricus noduli. 



III. On Roots. 



Polythalamous ; soft when young, woody when mature. At base 

 of trunk, or on strong roots, on surface of ground. October and 

 winter ...... Apliilotlirix radicis. 



Monothalamous, but often in irregular clusters on rootlets of old 

 trees. October and winter .... Biorhiza aptera. 



IV. On Bark. 



On young bark around a pruned branch, when cut off close to stem. 

 Early summer ..... Apliilotlirix corticis. 



V. On Flowers. 



Large mass of woolly hair, resembling a ball of cotton-wool. In 

 June and July . . . ... . Andricus ramuli. 



