200 Transactions. — Zoology. 



are larger than a very small pin's head, devour and annoy 

 these two animals, and are therefore friends of man. 



The great order Acarina, or mites generally, includes many 

 subdivisions, of which one is that of the Gamasince, or mite- 

 parasites ; and this, again, contains several genera, of which 

 one has received the name of Uropoda. It is the habit of 

 Uropoda to attach itself (not singly, but in clusters of as many 

 as can climb on) to the back of some insect or animal, pre- 

 ferably a more or less subterranean one, and there to live, 

 move, and have its being. A glance at the specimen which I 

 exhibit will show an unfortunate little beetle so completely 

 covered with numbers of mites that it is not easy to make out 

 its body. The specimen and its parasites are now dead, but 

 when they were alive it seemed not easy to understand how 

 so many mites could hang on to so small an object ; and it is 

 only by close observation and by trying to pull some of the 

 mites off that one discovers a very line silky hair fastened by 

 one end to the beetle and by the other to the mite, vdiich 

 effectually prevents the latter from falling off, and, indeed, 

 fastens it on rather firmly. Naturalists, I believe, are not yet 

 fully acquainted with the nature of this hair, or cord, though 

 Mr. Andrew Murray says that the mite can detach itself if it 

 pleases. Whether this is so or not it seems clear that the 

 victim has no such power ; and the condition of an insect or 

 of a woodlouse under these circumstances cannot be at all 

 enviable. 



Uropoda may sometimes, in wet weather, be found adher- 

 ing to stones instead of to animals ; but it would seem that 

 the congenial home of these mites is the skin of some other 

 small animal. 



On the stages of the two microscopes on the table are 

 shown specimens of mites taken in the one case from a wood- 

 louse (Oniscus sp.), in the other from a small click-beetle 

 (Elater), the full-grown form of the " wireworm." It will be 

 at once seen that both are yellowish-brown, oval, flatfish, and 

 hard ; and that they have the eight feet and the mouth-organs 

 characteristic of the true mites. Possibly very close observa- 

 tion might discover minute differences in the arrangement of 

 the bristly hairs visible on the surface of the body, and these 

 differences might suggest the separation of the specimens into 

 two species. I do not, however, see any necessity for this, 

 nor shall I attempt to distinguish these animals from the 

 European mites which are known to have precisely similar 

 habits. The present note has therefore been put forward only 

 to record the existence in New Zealand of these minute para- 

 sites, which, although apparently not very common, are doing 

 something to help man in his warfare against the enemies to 

 cultivation. 



