Messrs Warburton and Pearce, Note on a Collection, etc. 13 
Note on a Collection of Oribatidae from British. Guiana. 
By C. Warburton, M.A., Christ’s College, and N. D. F. Pearce, 
M.A., Trinity College. 
\Read 29 October, 1906.] 
The Oribatid mites are minute creatures, seldom exceeding 
one mm. in length, and often barely visible to the naked eye. 
It is only natural, therefore, that all except the very largest 
forms should escape the notice of the naturalists upon scientific 
expeditions, and of those who, dwelling in out of the way parts 
of the world, are good enough to collect and send home the 
more obvious specimens of insects and arachnids of their locality. 
The consequence is that our knowledge of the Oribatidae depends 
almost exclusively on species found in Europe and the United 
States — found, in fact, where naturalists who have studied this 
group can examine them on the spot. Nor did there appear any 
likelihood of our acquaintance with exotic Oribatidae being 
greatly extended, for even if an expert in Arachnology were 
present on a scientific expedition he would lack the time and 
the apparatus necessary for the collection and preparation of such 
small objects. 
There is no need to insist on the unsatisfactory nature of 
a classification based upon a very limited fauna in any group of 
animals. The Araneae furnish a striking example, as those 
animals were a few years ago precisely in the position now 
occupied by the Oribatidae. A more complete study of exotic 
spiders has completely revolutionised the classification of the 
group which had hitherto been based upon a very restricted 
fauna. 
We think it important to call attention to the fact that the 
small size of the Oribatidae need be no bar to a very thorough 
acquaintance with the group, for we find that consignments of 
moss or other matter in which they live sent from the most 
remote localities reach England in such a condition that the 
^tes can be captured and examined alive. The very minimum 
of t; ouble * s en ^ a ^ e ^ on collector, who has only to see that 
the n 10SS * s ’ n £ 00( ^ con dition and not too dry, and to pack it 
in tin* ma y be hermetically sealed without detriment to 
the livi 11 ^ contents. 
rph e fact is well illustrated in the case of some tins of moss 
which wt rece i ve d in July last from British Guiana. The moss 
