•234 



rHK KNTOMOI-OGISr. 



using the word "tail," instead of speaking of the " 12th and 

 13th segments," or the "posterior extremity;" it was done 

 for the sake of brevity, and not in disregard of the grammar 

 of the Science. 



DESCRIPTIONS OF OAK-GALLS. 



Translated from Dr. G. L. Mayr's ' Die Mitteleuropaischen Eicliengalli'U.' 



By Edward A. Fitch. 



(Continued from p. 209.) 



Fiff. 71. — S. TBICOLOR. 



Fig. 72. — S. AXBiPEs. 



71. Spatheyaster tricolor, Hart. — Although at the first 

 glance it is easy to separate S. tricolor from S. baccarum, 

 still the galls are much like one another. The gall of 

 ♦S". tricolor is also round, also contexturate with the leaf, 

 very sappy, and attains at most to a diameter of but 

 4"6 millimetres, and is covered, though not thickly, with 

 fine, soft, simple, very rarely branched, hairs, of from 1 to 2 

 millimetres in length ; the periphery of the gall is often 

 disturbed by small conical projections. The disk on the 

 under side of the leaf of Quercus sessilijlora, on which the 

 gall occurs, is smaller and less arched than in the gall of 

 S. baccarum. The figure is taken from specimens preserved 

 in spirit, which Herr v. Schlechtendal had the kindness to 

 send me. The fly appears, according to the same authority, 

 in the first fortnight of July, whilst liie gall may be found in 

 May.— G. L. Mayk. 



This species is at once distinguishable from the former by 

 its hairiness, as in Britain the ])ubescent galls oi S. baccarum 

 are unknown, owing to the absence of Quercus pubesceus. I 



