HYMENOPTERA — OAK GALLS. 161 



II. In Buds. 



Polytlialamous ; very large, spong}', apple-like. In terminal buds, 

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



Teras terminaUs. 



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

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



T'rii/o?i((sjns 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 ...... Ciinipi^ KoJlari. 



Spindle-shaped, with long peduncle. July and August 



Aphilotlirix callidoma. 



Ovoid, green, spotted, smooth, hard . Aphilotlirix alboimnciata. 



Gall wholly enveloped in leaf-scales . Aphilotlirix fecumlatrix. 



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

 April and May ..... Sputhegaster ap)rilinus. 



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

 ber ....... Aj^hilothrix r/lolmli. 



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

 inflated portion ...... Andricus injlator. 



Irregular swellings on twig .... Andricus noduli. 



III. On Roots. 



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

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

 winter ...... Aphilofhrix radicis. 



Monothalamous, but often in irregular clusters on rootlets of old 

 trees. October and winter .... Biorhizd aptera. 



IV. On Bark. 



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

 Early summer ..... Aphilothrix corticis. 



V. On Flowers. 



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

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



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