In the Preface to Vol. I of this book I mentioned the localities in which I myself, or those who had assisted me, had collected Oribatidœ. Since that time I have searched the following additional localities, viz. the New Forest in Hampshire, Ambleside in Westmoreland, and Keswick in Cumberland. Mr. E. Bostock has collected at Colwyn in Denbighshire, in the Isle of Anglesea, and at other places in North Wales; and Mr. M. J. Michael has collected at Gower in South Wales, at Malvern in Worcestershire, and elsewhere; I am also indebted to the last-named gentleman for the opportunity of examining a collection formed by him in the High Alps.<br><br>I have once more to thank all those whose names are mentioned in the Preface to Vol. I for their continued assistance, and especially Prof. T. Rupert Jones for his valuable aid in the laborious work of revising the sheets for the press.<br><br>During the year 1886 the sudden death of Mr. Rhein, who engraved all the plates in Vol. I and some of those in the present volume, made it necessary to seek other help in this department; therefore, the greater number of the plates in Vol. II have been placed on the stone by Mr. Horace Knight, on behalf of Messrs.