M. A. Scheuten on some Mites and their young states. 477 



leaf. Neither of them is a gall, but probably a fungoid pro- 

 duct ; that on the lime-tree is Erineum rubigo. 



The mites were always found on the lower surface of the leaf : 

 that of the pear-tree (fig. 4) is so small, as to be scarcely visible 

 on the leaf by the naked eye ; so quick in its movements, that it 

 can only be captured with difficulty ; and so tender, that it can 

 hardly be placed under the microscope without injury. It has 

 no eyes, the place of which appears to be taken by the anterior 

 legs, with which it is constantly feeling about. The long palpi 

 are also in constant motion, and bent downwards. After death 

 the legs and palpi contract closely together. 



The form of the mite is oval ; its length 0'30-0*34 mill., and 

 its breadth 0-17-0'19 mill. The parts of the mouth are conical, * 

 acute, and retractile. The five-jointed palpi are strongly hairy 

 and obtuse, with the apical joint set with bristles. The antennal 

 jaws are un distinguishable in the living animal ; but in glycerine 

 preparations, two claw-like jaws are seen (fig. 5). The palpi are 

 half- amalgamated with the rostrum. The legs are seven-jointed, 

 the first pair distinctly longer than the rest, the two intermediate 

 pairs shortest. The tarsal joint is furnished with a small funnel- 

 shaped sucker, which can be contracted, so as to appear like a 

 simple claw on the first pair of legs, when employed in feeling. 

 Behind the rostrum is a translucent spot, and there is another at 

 the hinder part of the body ; the rest is opake, and partly of 

 a reddish colour. No intestines or circulation could be dis- 

 tinguished in the living animal. 



The author once met with a remarkable form intermediate 

 between the larva and the mite (fig. 6). It was of the form of 

 the mite, but much smaller ; it possessed the four pairs of legs, 

 the anterior forming stumps ; the posterior styliform, terminating 

 in two bristles, and the first of them two-jointed. 



The second larva, found on a pear-tree (fig. 7), was doubly- 

 conical, forming an irregular rhombus with rounded angles. Its 

 size was nearly the same as that of the first larva, and the legs 

 and rostrum were similarly placed. The striae were undulated, 

 and the bristles dififerently arranged. This form rarely oc- 

 curred, but it was found at last amongst the very numerous 

 specimens of the former species upon the first pear-tree. The 

 perfect mite has not been found. 



The larva found on the leaves of the lime-tree (fig. 8) was 

 vermiform and dark brown ; the striae are only visible by the 

 employment of glycerine. It is O'lO mill, in length, and 0*37 

 mill, in breadth. The four 5 -jointed legs are longer than in 

 the first-mentioned species, but the relative position of the legs 

 and rostrum is the same. A sucking-tube of 0*01 mill, in length 

 was seen in one individual. The body is undulated, somewhat 



