DESCRIPTIONS OF OAK-GALLS. 



133 



kinds of morbid growths which are especially constant; but 

 just as in animal disorders we frequently deal with the 

 svraptoiiis rather than with the evil itself, so in the vegetable 

 world it is only by minute observation backwards, step by 

 step, from the completed morbid growth that we can hope to 

 arrive at its origin, and thence possibly at its cause. 

 Maldon, Essex, April 3, 1878. 



DESCRIPTIONS OF OAK-GALLS. 

 Translated from Dr. (t. L. Mayr's ' Die Mitteleuropaischen EiclieuKalleii. 



By Edward A. Fitch. 



(Continued from p. 115." 



Fig. 84. — Andricus quadiulineatus. 



Fig. 80. A. PEDUNCULI. 



Fig. 8G. 



A. VERRTICOSV: 



84. Andricus quadrilineatus. Hart. 85. A. pedunculi, 

 Schenck. — Professor Schenck, in his ' Beitrage zur Kenntniss 

 der nassauischen Cynipiden und ihrer Gallen,' published in 

 1865, described a number of gall-species which are produced 

 on the catkins of the oak, and which resemble one another in 

 appearance very closely. Almost the whole of these forms he 

 described from the specimens which are contained in Von 

 Heyden's collection. Tlnough the kindness of Herr v, 

 Heyden I have been enabled to examine these types, so that 

 I am now in a position to rectify some errors respecting 

 those which belong here. Galls collected by me both last 

 year and in the present still contain larvae, consequently 

 there has been no emergence. The species which 1 have 

 taken into consideration are Andricus quadrilineaiun. Hart., 

 A. Jlaiuoniis^ Schenck, A. jjeduticuli, Schenck, A. ainbi- 



