70 BRITISH OAK GALLS. 
Andricus solitarius, Mayr. 
(Plate XV.) 
Diplolepis solitarius, Fonsc.; Cynips ferruginea, Hartig, Schenck ; 
Aphilothrix solitaria, Fonsc., Mayr, Fitch; Andricus solitarius, 
Cameron, Mosley. 
English names of gall.—The Hairy Spindle Gall,” “The 
Red-haired Bud-gall.” ; 
Position of gall.—Develops from a terminal or axillary bud. 
Manner of growth.—Solitary, pubescent, spindle shape. 
Colours.—Green, yellowish-brown, brown, reddish-brown.‘ 
Average dimensions of a mature specimen.— Height, 
10 mm.; breadth, 4 mm.; girth, 12 mm. 
May be sought during the months of June to September. 
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 
September. 
‘Parasites, Nos. 38, 46, 66. Inquilines, Nos. 130, 136, 145. 
Cameron appears to have been the first to describe 
this gall for Britain. He found specimens in Cadder 
Wood, near Glasgow. In the years 1873-5 it was 
also found in Nottinghamshire by Mr. G. B. Rothera 
and Dr. Ransom. 
It is now distributed with moderate frequency all 
over the country, growing more generally on bushes 
in woods than on branches and twigs of trees. In 
some localities it is abundant, in others seldom or 
never seen. 
The specimen in the inset of Plate XV is unusual in 
having a small mamelon on its surface. The per- 
sistent leaf-scales, characteristic of this species, at the 
base of the gall are also easily noticeable. 
This species is of remarkable appearance and vari- 
able in form, situated indiscriminately in terminal 
and axillary positions. Easily recognised by being 
profusely covered with glossy and soft hairs of a 
ferruginous colour, which are longer and denser at 
the apex of the gall than elsewhere. When maturity is 
