I wish distinctly to disclaim offering the present volume as a compendium of the Natural History of Ceylon. I present it merely as a "mémoire pour servir," materials to assist some future inquirer in the formation of a more detailed and systematic account of the _fauna_ of the island. My design has been to point out to others the extreme richness and variety of the field, the facility of exploring it, and the charms and attractions of the undertaking. I am eager to show how much remains to do by exhibiting the little that has as yet been done. The departments of _Mammalia_ and _Birds_ are the only two which can be said to have as yet undergone tolerably close investigation; although even in these it is probable that large additions still remain to be made to the ascertained species. But, independently of forms and specific characteristics, the more interesting inquiry into habits and instincts is still open for observation and remark; and for the investigation of these no country can possibly afford more inviting opportunities than Ceylon. Concerning the _Reptilia_ a considerable amount of information has been amassed. The Batrachians and smaller Lizards have, I apprehend, been imperfectly investigated; but the Tortoises are well known, and the Serpents, from the fearful interest attaching to the race, and stimulating their destruction, have been so vigilantly pursued, that there is reason to believe that few, if any, varieties exist which have not been carefully examined. In a very large collection, made by Mr. CHARLES REGINALD BULLER during many years' residence in Kandy, and recently submitted by him to Dr. Günther, only one single specimen proved to be new or previously unknown to belong to the island. Of the _Ichthyology_ of Ceylon I am obliged to speak ill very different terms; for although the materials are abundant almost to profusion, little has yet been done to bring them under thoroughly scientific scrutiny. In the following pages I have alluded to the large collection of examples of Fishes sent home by officers of the Medical Staff, and which still remain unopened, in the Fort Pitt Museum at Chatham; but I am not without hope that these may shortly undergo comparison with the drawings which exist of each, and that this branch of the island _fauna_ may at last attract the attention to which its richness so eminently entitles it. In the department of Entomology much has already been achieved; but an extended area still invites future explorers; and one which the Notes of Mr. Walker prefixed to the List of Insects in this volume, show to be of extraordinary interest, from the unexpected convergence in Ceylon of characteristics heretofore supposed to have been kept distinct by the broad lines of geographical distribution.