The Scottish Naturalist. 279 



in hollows of the leaf, occupying the central spaces between the 

 nerves. There is seldom any mark of their presence, except an 

 occasional slight discolouration on the upper surface of the leaf. 

 Several patches may exist on a leaf, but they show no tendency to 

 fuse together, and are usually a little distance apart. The hairs 

 are short, pyriform or obovate, and shortly stalked, with thin 

 membranous cell wall, marked with longitudinal folds. This gall 

 has been recorded from numerous localities on the Continent of 

 Europe. 



d. Legnon circumscriptum Bremi ; the galls of this mite consist 

 of the involute and slightly thickened margins of the leaves, some- 

 times extending almost entirely around the leaf, but usually only 

 in parts of from 5 to 50 mm. in length. The affected portions 

 form tubes not exceeding 1 mm. in diameter, and generally on 

 cross section show about 1^ turns. The interior of the tube 

 contains some hairs, the usual marginal hairs of the leaf, among 

 which live the mites, as usual belonging to the genus Phytopius. 

 The tissue of the gall is slightly more fleshy than that of ihe 

 healthy leaf, but the colour is lit lie changed, though becoming 

 brown and dry rather earlier than the rest of the leaf. These galls 

 were abundant on the same trees, and often on the same leaves as 

 the Erineum ; probably they are not rare in Scotland in certain 

 localities, though so inconspicuous as to be readily overlooked. 



AGROSTIS ALBA L. :— 



a. Galls of Tylenchus ? on the leaves (" Sc. JVat.," VI, 17). 



b. Pseudogalls of Brachycolus Stellarice. Hardy on the young 

 leaf-shoots, quite similar to, but less conspicuous than those on 



HOLCUS MOLLIS L. 



In both these grasses in autumn one very frequently finds shoots 

 remaining short, stunted, and clubbed, the leaves being crowded 

 and showing a tendency to become fleshy at the base. Between 

 the bases of the leaves are numbers of wingless long-bodied 

 Aphides, of the species mentioned above (see Buckton's " British 

 Aphides;' Vol II., 147-8, pi IXXXV., f. 1-3). The galls on 

 Holcus are extremely common in many places ; on Agrostis they 

 are less frequent. In spring one meets with similar pseudogalls, 

 formed by the same insects, on Stellaria Holostea and on Cerastiu?n t 

 as already noted under these plants. 



FESTUCA OVINA L. 



In August, 1882, and again in July, 1S83, I found in various 



