202 Professor Trail on the [sess. lh. 



tinued attacks of the larvte and pupae, which may be found 

 in muhitudes living amid a whitish woolly secretion, between 

 the inflated and imlnicated leaves of the terminal buds. The 

 pseudo-galls may reach the size of a large walnut, though 

 frequently not exceeding that of a hazel-nut; but for a 

 while they do not change colour from the normal green. 

 The inflorescences are very often involved, and remain 

 stunted and abortive. This gall has not been recorded as 

 British ; but there is a gall of very frequent occurrence on 

 various species of Gerastmm. in Scotland that very much 

 resembles its smaller forms. The Scotch gall is the work of 

 an aphis {Brachycolus Stellariw, Hardy), which lives upon 

 Cerastium sps. and Stellaria Holostca in early summer, and 

 produces similar galls on Holcus lanatus, Agrostis alba, and 

 other grasses in autumn. Trioza Cerastii has been recorded 

 pre\dously from Bohemia, Thuringia, Silesia, Bavaria, the 

 Tyrol (where I have found its galls in the Brenner Pass), 

 Lower Austria, and Abo in Finland. I have also found 

 it on the Eigiin Switzerland. 



Tilia parvifolia, Ehrh. — All the galls about to be men- 

 tioned from this tree were found in the vicinity of Eide, on 

 13th August 1887. They all appear to be identical with 

 galls already described from Central Europe, some of which 

 also are found in Scotland ; but from several of them the 

 rnak(;rs have not yet been reared, and 'they bear only pro- 

 visional names. 



1. A leaf bearing several of the unmistakable galls of 

 Hormomyia Rcaimmtriana, F. Loew, was found by Professor 

 liower, and given l)y him to me. The galls ai'e scattered in 

 the leaf-blade, projecting like a cone botli above and below, 

 the lower cone being the more acute. When mature they 

 open (to allow the larva tf) emerge) by a kind of lid on the 

 upper surface. Though not known as Scotch, these galls are 

 not rare in Central Eur()])e. 



2. On several trees the leaves and bracts bore numerous 

 examples of the very inconspicuous blister-like galls of 

 CecidoiiiyUi Frauenfeldi, Kalt. From two to eight may be 

 found on a leaf, scattered over the surface. When fresh 

 they can hardly 1)0 detected, except on a close search, as 

 they project very little aljove the general surface, and do not 

 differ' from it in colour. Their lower surface is rather the 



