TEKAS TERAIINALIS. 137 



as indicated in its trivial name, it is blister-like in its 

 mode of expansion. Seldom more that two appear on 

 a leaf. They may be on either side of the mid-rib, or 

 coalescent; occasionally absorbing part of a small 

 vein, but rarely, if ever, on the mid -rib. When on 

 a lobe of the leaf distortion is sometimes produced 

 similar to that caused by >S'. albipes. 



During many years of research I have on several 

 occasions noticed galls on leaves of stub-oaks, very 

 similar to S. vesicatrix. Small blisters, about 3 mm. 

 in diameter; irregular peripherj^; when in nerve axils, 

 triangular; without radii, grooves, or papillae. Pale 

 green, and greenish-yellow, broadly margined with 

 red. The interior fully occupied with a pure w^hite 

 apodous larva, cecidomyian in shape, about 2 mm. 

 long and -o mm. at widest part. It eats its way out 

 and falls to earth to pupate. Afterwards the supra 

 convexity becomes concave. I have neither l^een able 

 to have the larva identified, nor rear the imago. 



Teras terminalis, Fabiicius. 

 (Plates LVI, LVII.) 



Cynips quercus-terminalis, Fabri. ; Andricus terminalis, Fabri., 

 Mayr, Walker, Fitcli ; Teras terminalis, Miiller, Marshall, Adler ; 

 Biorhiza terminalis, Cameron. 



English names of gall. — " The Oak Apple," " King Charles' 

 Apple," " The Apple Gall."" 



Position of gall. — Axillary and terminal on twigs. 



Manner of growth. — Single, glabrous, glossy, globular, 

 spongy. 



Colours. — Yellowish-white, suffused with pink and red, pale 

 brownish yellow. 



Average dimensions of a mature specimen. — Diameter, 

 25 mm. 



May be sought during any mouth of the year. 



Growth is complete by the end of June. 



The typical condition of the gall is plurilocular but unilarval. 

 Usual number of cells altout thirty. 



The larvae pupate in the gall. The imagines emerge during 

 June and Julv. 



