190 THE ENTOMOLOGIST. 



thought was a ball of sheeps' wool in a meadow where there 

 were no sheep, and I placed it under a glass clock-shade for 

 security. This morning I found the clock had stopped, and 

 a quantity of flies were in the case and in the works of the 

 clock* I never happened to have seen a similar growth on 

 the oak, a sprig of which is visible in the woolly gall, and I 

 have sent some of the flies in spirits. There are more 

 hatched out in the box since I placed the oak-gall in it." 

 How many specimens of the Cynips hatched in the clock- 

 case does not appear, but the box exhibited was found to 

 contain upwards of eighty. 



Acarid(B in the Buds of Black Currant. — Prof. Westwood 

 made some observations on a very minute form of Acavidae, 

 to which he had already directed the attention of the 

 Society ; they were about 2^-^ of an inch in length, found in 

 the unopened buds of the black currant, the blossom of 

 which they destroyed ; they were elongate, cylindrical and 

 fleshy, and possessed only four legs. A somewhat similar form 

 found in galls was some years ago described in France; and 

 the Rev. M. J. Berkeley had recently called Prof. Westwood's 

 attention to a third form which attacks pear trees, and makes 

 small patches or pustules on the leaves. At Oxford he had 

 found many of these blotches, and as many as thirty or forty 

 Acari in a single blotch; in some cases there was a small 

 opening in the leaf, but in the majority there was no visible 

 aperture; perhaps the parent, when depositing her eggs, 

 makes a small hole which afterwards closes over. Notwith- 

 standing the existence of only two pairs of legs, he thought 

 these were a mature form ; and the three species seemed to 

 constitute a distinct four-footed tribe in the family Acaridae, 

 distinguished likewise by having the whole surface covered 

 with minute tubercles (like the parasite of the human nose) 

 arranged in as many as sixty transverse rows ; at auy rate 

 they required to be segregated under a separate generic 

 name, and he proposed that of Acarellus, the three species 

 being Acarellus Pyri, A. Ribis-nigri, and A. Gallarum. Mr. 

 Mr. Albert Muller suggested that these forms perhaps 

 belonged to the already-named genus Phytoptus or Phytopus, 

 the species of which inhabit excrescences of various plants, 

 had at one stage of their existence only four legs, and are 

 closely allied to Simonea Follicidorum. 



