98 ANDRIOUS OIRRATUS. 



dirigee de liaut en bas, et marquee de quelques cotes 

 longitudinales tantot assez saillantes et tantot presque 

 effacees." Mayr (Cyn. Gallen, p. 21) says that colli- 

 doma, Gir., and callidoma, Adler, are different 

 species, and that the galls only through the pubes- 

 cence are to be distinguished. As regards this latter 

 point I may add that I have some young galls and 

 some half-developed ones, inhabited by inquilines of 

 callidoma, which bear a distinct whitish pubescence, 

 depressed, moderately long, and directed from base to 

 apex, but not very thick. As regards the distinction 

 between the flies, I am unable to fix upon any tangible 

 characters from the description of Giraud and Adler 

 by means of which they could be recognised ; and 

 therefore I am inclined to look upon the two as iden- 

 tical. 



It is worthy of note that the bud from which the 

 gall originates is not distorted in any way. 



Inquilines. — Synergus nervosus and S. vulgaris. 

 Giraud says that he has bred Ceroptres from the gall 

 (1. c), but no species is mentioned. Ratzeburg records 

 Siphonura brevicauda as a parasite. 



Sexual Form.— Black, shining; the abdomen brownish-red, darker 

 above ; the legs uniformly citron-yellow (except the coxse at base) ; the 

 antenna yellowish-testaceous, somewhat infuscated at the apex. Wings 

 clear hyaline ; the tegulae and a line on the pronotum pallid-yellow. 



The ^ similar. 



Length l - 5 mm. 



Readily known by the uniform citron-yellow legs. 



Gall. — Found in the c? catkins in May. Length 

 about 2 mm. ; oval, rounded at base and apex ; green 

 when young, brownish and rough when old. From 

 its base there issues from the stamens long white 

 woolly hairs, which may be three or four times as 

 long as the gall itself. They usually are placed in 

 clusters at the bud, and form a mass of wool about 

 5 — 7 mm. in length and breadth. The catkins are 

 shortened by the galls, and seldom project much 

 beyond the bud. 



I have found the galls of callidoma in Glen Moriston 



