"The sections descriptive of the several classes are accompanied by lists, prepared with the assistance of scientific friends, showing the extent to which each particular branch had been investigated by naturalists, up to the period of my departure from Ceylon at the close of 1849. These, besides their inherent interest, will, I trust, stimulate others to engage in the same pursuit, by exhibiting chasms, which it remains for future industry and research to fill up;--and the study of the zoology of Ceylon may thus serve as a preparative for that of Continental India, embracing, as the former does, much that is common to both, as well as possessing a _fauna_ peculiar to the island, that in itself will amply repay more extended scrutiny. "From these lists have been excluded all species regarding the authenticity of which reasonable doubts could be entertained[1], and of some of them, a very few have been printed in _italics_, in order to denote the desirability of more minute comparison with well-determined specimens in the great national depositories before finally incorporating them with the Singhalese catalogues. [Footnote 1: An exception occurs in the list of shells, prepared by Mr. SYLVANUS HANLEY, in which some whose localities are doubtful have been admitted for reasons adduced. (See p. 387.)] "In the labour of collecting and verifying the facts embodied in these sections, I cannot too warmly express my thanks for the aid I have received from gentlemen interested in similar studies in Ceylon: from Dr. KELAART[1] and Mr. EDGAR L. LAYARD, as well as from officers of the Ceylon Civil Service; the Hon. GERALD C. TALBOT, Mr. C.R. BULLER, Mr. MERCER, Mr. MORRIS, Mr. WHITING, Major SKINNER, and Mr. MITFORD. [Footnote 1: It is with deep regret that I have to record the death of this accomplished gentleman, which occurred in 1860.] "Before venturing to commit these chapters of my work to the press, I have had the advantage of having portions of them read by Professor HUXLEY, Mr. MOORE, of the East India House Museum; Mr. R. PATTERSON, F.R.S., author of the _Introduction to Zoology_; and by Mr. ADAM WHITE, of the British Museum; to each of whom I am exceedingly indebted for the care they have bestowed. In an especial degree I have to acknowledge the kindness of Dr. J.E. GRAY, F.R.S., for valuable additions and corrections in the list of the Ceylon Reptilia; and to Professor FARADAY for some notes on the nature and qualities of the "Serpent Stone,"[2] submitted to him. [Footnote 2: See p. 312.]