56 BRITISH OAK GALLS. 
The gall consists of two thin layers, and an mner 
loose larval chamber. 
The colour of the external layer is dark-yellow; 
that of the internal layer reddish-brown, the larval 
chamber more or less yellowish. 
The imago which causes the gall appears to prefer 
to oviposit among the highest branches of the tree. 
A peculiarity about this gall has been observed, viz. 
that they fall to the ground after the first frost, 
retaining the bud-like scales attached to their base. 
When A. globuii falls to the ground the scales have 
either previously dropped off or they are left on the 
twig. : 
z globuli has never been observed so high up on the 
tree as Andricus clementine grows. 
Andricus curvator, Hartig. 
~ 
(Plates VI, VII.) 
Andricus curvator, Mayr, Miiller, Fitch, Adler; A. perfoliatus, 
Schenck; A. dimidiatus, Schlechtdl.; Cynips curvator, Thomson ; 
C. axillaris, Hartig. 
English name of gall.—‘ The Curved Leaf Gall.” 
Position of gall.—On blade, mid-rib, or petiole of leaf. 
Manner of growth.—Glabrous, glossy, single, conglomerated, 
anastomosing. 
Colours.—Pale green, light brown. 
Average dimensions of a mature specimen.— Length, 
8mm.; breadth, 8 mm.; girth, 24 mm. 
May be sought during any month of the year. 
Growth is complete by the end of July. 
The typical condition of the gall is bilocular, but unilarval. 
The larva pupates in the gall. The imago emerges during 
August. 
Parasites and inquilines are given on p. 58. 
Alternate agamous generation: Aphilothria collaris, Hartig. 
This gall is widely distributed throughout Britain. 
It appears in the form of a swelling of the young 
leaves of both species of oak, as plentifully on young 
