118 BRITISH OAK GALLS. 
In its normal and typical condition there are several 
distinctive features. (a) Itsaverage diameter (3 mm.) 
is less, (b) the upward curve of its rim is more pro- 
nounced, (c) the central papilla is not so distinct, (d) 
the under-surface is rarely whitish or yellowish, (e) nor 
is it usually so abundant as N. lenticularis. 
The mode of attachment to the leaf is by means of 
an extremely short and thin peduncle which retains 
the gall with considerable tenacity until the autumn, 
when it decays and the gall falls from the leaf. The 
moisture of the earth allows development to continue 
gradually until the gall is about double its former 
thickness. 
Cameron remarks: “The larva does not develop 
until April, being later in its development than lenti- 
cularis and numismatis, the imago not appearing until 
May ” (‘ Brit. Phyto. Hymen.,’ vol. iv, p. 134). Adler 
also says: “ Although these galls fall to the ground in 
October it is only during the month of March [of the 
following year| that larval development begins; 
towards the end of April it becomes a pupa, and the 
perfect insect appears in May” (‘ Alternating Genera- 
tions,’ p. 28). 
Some years this gall, in common with the other 
Neuroterus species, occurs in extraordinary abundance, 
not only as regards the number of oak leaves bearing 
galls, but the profusion of the galls on the leaves. 
The autumn of 1907 was such an occasion. 
Neuroterus leviusculus, Schenck. 
(Plate XLVIT.) 
Neuroterus pezizeformis, Schltdl.; N. leviusculus, Mayr, Adler, 
Fitch, Schenck, Licht., Cameron; Spathegaster albipes, Schenck, 
Licht., Mayr, Adler. 
English name of gall.—‘‘ The Smooth Spangle Gall.” 
Position of gall.—-On the under-surface of the leaf. 
Manner of growth.—Glabrous, glossy, separate, scattered, 
cupulate. 
