30 A. D. MICHAEL ON GLYCIl'HAGUS PALMIFER. 



a creature as this, particularly when inhabiting cellars and places 

 whence goods are exported to foreign countries, is very easily 

 carried with those goods, and very easily spread afterwards, when 

 those, or other goods lying near them, are sent from one place to 

 another ; and this reason appears to me to render it always very 

 difficult to say whether such creatures are indigenous or introduced ; 

 and in the next place, because, at the suggestion of Mr. Murray — 

 whose loss we all of us, I am sure, deplore — I caused enquiries to 

 be made, and ascertained that some three or four years ago my 

 friends imported a cask of claret from Bordeaux, which was stored 

 for a time in part of the cellars not very far from where I found my 

 specimens : there are not any to be found now, either in the place 

 where the cask was kept or on the cask itself, but they might have 

 migrated to a more congenial place. After a day or two a thaw 

 came on; and the cellar wall streamed with damp, I then failed 

 to find any more ; but I brought up some scrapings from the wall 

 from which I have since bred several. 



The genus Glyciphagus belongs to the true Acaridaa : it is 

 characterised by a pointed rostrum with chelate (nipper-like) man- 

 dibles ; a dorsal depression instead of a distinct transverse line 

 between thorax and abdomen ; a five-jointed leg, with the tarsus 

 terminated by a small sucker and very small single claw ; and par- 

 ticularly by three peculiarities, viz. : — lstly, the skin of the 

 back being plicated to such an extent as to present a velvety appear- 

 ance ; 2ndly, the body in the females being terminated by a short 

 projection, or anal button, as Murray calls it ; and, ordly, the hairs 

 or some of them being either plumose or developed into the remark- 

 able leaf-like expansions which I am about to describe. 



MM. Robin and Fumose divide the genus into two sections, th<> 

 second section containing the present species, and being distin- 

 guished by the body being shorter, smaller, and less indented, the 

 skin more wrinkled and velvety, and the hairs either very plumose, 

 as in G. plumiger, or else developed in the remarkable manner 

 which is observed in this species only ; but before describing these 

 I will pause for an instant to point out that this may be considered 

 the culminating point of that series of hair developments which the 

 mites present. In the first place we have the simple hair, as in Tyro- 

 glyphus, then in such a species as Trombidium curtipes we have 

 the knobbed hair so well known in plants. Then, in Pteroptus and 

 Otonysus, we have the imbricated hair like that of the bats, a fact 

 which Mr. Murray justly remarks is very singular, since both of 



