88 BRITISH OAK GALLS. 
This gall stands more or less obliquely from the 
twig, upon a hemispherical base formed of the aborted 
bud out of which it has grown. It.may be sessile, or 
attached by a short peduncle. It is in the form of 
a narrow cylinder, the distal end of which bears a 
small, glabrous, glossy, mastoid process. 
Its growth occupies about three weeks, by which 
time it reaches maturity and then falls to the ground. 
A special feature characterising the growth of this 
gall is the hemispherical reddish-brown base which is 
firmly adherent to the twig in a leaf axil. 
The gall appears to be rare. I have never found 
more than the one specimen illustrated, although 
a. After Cameron, 
s,c. After Adler, each x 2. pv. The same specimen as in Plate 
XXIII, div. A. x 4. dele. ad nat. H.C. 
quantities of galls of Andricus nudus are found year 
after year in the same wood. I found it in a wood at 
Hastings during September 1901, and knowing for 
certain that I should not be able to ‘visit the spot again 
for several weeks, gathered it, but unfortunately failed 
to rear the inhabitant. . 
Cameron describes the gall as smooth. My speci- 
men is clothed with numerous short, recurved, 
adpressed hairlets, of a somewhat golden colour, 
except at the apex, and devoid of ridges. Adler does 
not refer to the presence or absence of hairlets. 
Cameron’s illustration (‘ Brit. Phyto. Hymen.,’ vol. iv, 
Plate VII, fig. 2) corresponds as regards position, base, 
size, and partly in outline, with my specimen. 
Adler, in ‘ Alternating Generations,’ Fig. 12, illus- 
trates two galls on a twig. They are sessile, and 
