214 The Scottish Naturalist. 



the name of which I had not discovered. This autumn I have 

 found the same species of Aphis on Holcus lanatus, L. in several 

 locaHties near Aberdeen. The effects produced on the grass are 

 similar to those produced on the Stitchwort. The shoots remain 

 short, with the leaves short, concave, slightly thickened, and 

 crowded, and overlapping one another. Between the leaves live 

 numerous Aphides j but I have not seen winged insects among 

 them. Mr Hardy has described this insect under the name 

 Aphis stella7'i(B {' North British Agriculturist,' ii. 788), and has 

 described the galls formed by it on S. ho/ostea, S. graminea, 

 Cerastiiim triviale, and Holcus mollis. 



The insects, of which only the wingless forms are yet known, 

 are also described and figured under the name Brachycolus stel- 

 larice. in Buckton's 'British Aphides,' ii. 147-149, PI. 85, 

 figs. 1-3. 



TiLiA EUROP^A, L. — {b) On one or two trees in Old Aberdeen, 

 in the month of July, occurred galls of a Cecidomyia (?). The mar- 

 gins of the leaves are rolled up so as to form a tube, and become 

 thickened, fleshy, and of a red colour. Each is tenanted by one 

 or more reddish-orange larvse, which leave the gall when full fed. 

 These galls are most common on young shoots from the root or 

 from the trunk of the tree. 



{c) Erineum tiliaceuni, Persoon. — Leaves (apparently of T. 

 g7'a7idifolia) sent me from Perthshire by Dr Buchanan White 

 bear on their lower surface patches of this gall, the work of a 

 Phytoptus. These patches are scattered over the surface of the 

 leaf, are irregularly rounded in outline, are usually about ^ inch 

 across, and are nearly white in colour. On examination through the 

 microscope, they are found to be made up of a multitude of rather 

 slender and nearly colourless filaments, often somewhat twisted : 

 among these live the four-footed mites. The upper surface of 

 the leaf, opposite the patch, usually becomes reddish in colour. 

 These galls have frequently been described by French and 

 German writers. 



Acer pseudoplatanus, L, — {a) Nail-galls oi Phytoptus = Cera- 

 toneoii vulgare, Bremi ('Scot. Nat.,' iv. 14) 



{b) Erifieiun acerinu?n, D. C. — Another mite-gall found scat- 

 tered over the leaf in irregularly- rounded patches %-y2 inch 

 across — several such patches often occurring on a leaf. The 

 patches consist, as on Tilia, of elongated clubbed hairs, usually 

 twisted or incurved, at first probably pale coloured, but soon the 

 patch becomes dark rusty brown. Among the hairs live the 



