APHILOTHRIX CALLIDOMA, 77 
Aphilothrix callidoma, Hartig. 
(Plate XVIII.) 
Cynips callidoma, Thomson ; Andricus callidoma, Mayr, Cameron ; 
Aphilothriz callidoma, Licht., Mayr, Fitch, Adler, Mosley. 
English name of gall.—“ The Stalked Spindle Gall.” 
Position of gall.—Axillary buds. 
Manner of growth.—Solitary, glabrous, glossy, spindle shape. 
Colours.—Pale green, green, yellowish-green, brown. 
Average dimensions of a mature specimen.— Length, 
18 mm. ; girth, in centre, 9mm. 
May be sought during the months of May to October. 
Growth is complete by the end of August. 
The typical condition of the gall is unilocular and unilarval. 
The larva pupates in the gall. The imago emerges during the 
following spring. 
Parasite, No. 111. Inquilines, Nos. 138, 145. 
Alternate sexual generation: Andricus cirratus, Adler. 
The elegant shape and marked originality in the 
form of this gall distinguishes it above all other 
British oak galls. 
It grows from an axillary bud, but more frequently 
on the slenderest twigs of stub-oaks, and near the 
ground, than in any other situation. Once only have 
I found a specimen on a branch as high up as ten 
feet from the ground. It is shown as an inset in 
Plate XVIII. 
The gail is cylindrical in outline, with each end 
attenuated, producing a fusiform or spindle-shaped 
growth. Each attenuation is solid, usually of great 
length, the basal one generally the longest, sometimes 
twice or three times longer than the central portion ; 
the distal end may be short and recurved. 
The larval chamber is situated in the centre. During 
growth it is difficult to decide without dissection where 
the gall is solid—the enlargement is so gradual. When 
dry the attenuations shrink (in thickness only) almost 
to a thread. As the larval chamber does not shrink 
it can then be easily located. Its cell walls are very 
