GALL MITES, 367 



:ase paratively long bristles at the back. V. Frauenfeld states that he 

 found this Phytoptus at the end of July and August of a reddish- 

 brown colour. 



ErINEUM rULCHELLUM, Schl. ? 



Oblong, bare, stool-like dots, more or less raised, on the upper 

 side of the leaf and up in the angles of the rib, and along the mid 

 rib of the leaves, like those already mentioned on the leaves of 

 the alder. They are occasionally but seldom found by themselves 

 on the side of the leaf near the edge between the leaf nerves. 

 They are to be found on the first leaves of the young shoots, are 

 darker coloured than the leaf, and filled inside with a long brownish 

 Erineum, which consists of worm-shaped short hairs, harbouring 

 bro\^Tiish mites irt no great numbers. 



Phytoptus carpini, Ajji. 

 This occurs on the side-rib of a leaf, in a fold between which 

 the larvae live, often in thousands. This is probably the Phytoptus 

 carpini of Frauenfeld (Kirchner). 



Malotrichus carpini, Am. 

 This mite is found on the underside of the leaves in the axil of 

 the leaf nerve, and causes tliere a hairy cushion-like formation. 



VOLVULIFEX rhodizans, Am. 



Another kind of mite gall appearing on the upper side of the 

 leaves of the Hornbeam, like purses, with carmine-red and rose- 

 red hairs. 



On the Willow. 



Phytoptus Sp. 



Narrow rollings of the edge of the leaf upwards, which resemble 



those 'which occur sometimes on the leaves of the pear tree. 



They extend always only on a short part of the edge of the leaf, 



