The Scottish Naturalist. 31 



usually near the surface of the ground ; they are apt to be 

 united, forming masses, but usually each gall, when distinct, 

 is about y^' diameter. Each is monothalamous ; the walls 

 are thick and fleshy, the part projecting from the root 

 forms an irregular hemisphere, the surface of which is 

 smooth and whitish, Those on B. si?iapistrum are very 

 common about Aberdeen, and also occur in Strathdon ; 

 those on R. raphanistrum are less common, and are less 

 apt than the former to form large masses. Probably both 

 are formed by Ceut/wrhynchus, but I have not yet reared the 

 insects. 



Helianthemum vulgare Gaertn. — The galls occur at the 

 tips of the leaf-shoots, and consist of modified buds, the 

 leaves . of which are thickly covered with whitish hairs. 

 They are sessile, ovate, and rather more than %' in length. 

 Between the~ leaves live one or more larvae of Diplosis 

 helianthemi, Hardy? The galls are common at Muchalls, 

 Glen Gairn, Strathdon, &c, in the district of ' Dee,' and at 

 Lintrathen in Forfarshire. 



Cerastium glomeratum Thuill. — The terminal bud becomes 

 affected, either the whole or the basal half of each leaf in it 

 becoming swollen, hard, and fleshy ; in the centre is a small 

 cavity. In form the gall is somewhat ovate, the average 

 breadth being about ^', the length rather more. In colour 

 it is light yellowish-red, the surface smooth, save at the 

 margins of the leaves, where there is a fringe of long hairs. 

 Each contains several Cecidomyious larvae, each of which 

 spins a small white cocoon in the gall in autumn. These 

 galls are not uncommon around Aberdeen, from August to 

 October. I also found one in September, near Dunkeld. 



Hypericum pulchrum L. — The galls on this are similar in 

 origin and structure to the last, the basal two-thirds of the 

 leaflet of the terminal bud of the leaf-shoot becoming inflated, 

 red and fleshy; the leaves diverge slightly above ; average 

 size %' by }i' '. The surface is smooth and naked. Be- 

 tween the leaflets live several small reddish-orange larvae of 

 Cecidomyia serotina Winnertz?. Shown me by Dr. Buchanan 

 White, near Dunkeld, in September. 



