356 ARACHNOIDEA. 



XVI. Section II. — Species Living in Galls. 



12—16. Phytoptus TILI.T,, which produces the lime-leaf nail-gall (Ceratoneon ex* 

 tensum, Bremi). — 12. Specimen of leaf bearing these galls ; 13. Sketch 

 of ditto ; 14. Magnified sketch of galls j 15. Magnified section of gall, 

 showing the interior full of hairs ; 16. Magnified figure of the mite, 

 copied from Dujardin's figure. 



We have already given a figure of this gall and its maker in 

 illustration of our general remarks. The gall is green when young 

 and then becomes yellowish, and passes successively through red, 

 crimson, purple, into brown. This gall also occurs on the Tilia 

 argentea. There are two or three other mite galls that occur on 

 the leaf of the common lime tree or its allies on the Continent, and 

 may, perhaps, also be found in this country. One is a yellow, red 

 hairy, half-cone-shaped gall, which appears in the angles between 

 the ribs ; very rarely elsewhere. On a section being made, it is 

 found to be divided into two, forming a double-roomed house. 

 Another one, very like this, but dark coloured, is also described 



There is a fourth species named Legnon crispum by Bremi, which 

 makes a marginal swelling on the leaf; a fifth, which we shall call 



Bract of Tilia parvifolia with margin of leaf rolled in by Phytoptus tiliarius 

 Copied from figure by Low. 



Phytoptus tiliarius, makes knotty, curled-in margins on the bracts- 

 of the flower of Tilia parvifolia ; and a sixth (Phyllerium tiliaceum, 

 Pers.) which makes little lumps on the under side of the leaf. 



Nos. Phytoptus aceris (Volvulifex aceris, Amei-ling, which produces Ceratoneon> 

 «7— 33- vulgare, Bremi, on the leaf of the sycamore). — 17. Sycamore leaf bear- 



ing galls of ditto ; 18. Sketch of ditto ; 19. Sketch of leaf of variegated 

 sycamore (Acer pseudoplatanus, var. Leopoldi), bearing galls of ditto ;. 

 20. Specimen of ditto ; 21. Leaf of sycamore bearing galls on under 

 side, showing the woolly entrance to the gall ; 22. Sketch of ditto j. 

 23. Magnified section of gall of ditto. 



