EDITOR’S ADVERTISEMENT. 
Wuen my esteemed and lamented friend, the Author of the present 
Work, was removed from the scene of his useful and benevolent 
labours, he had made considerable progress towards its completion. 
Most of the plates had been engraved or lithographed, and nearly 
two-thirds of the letter-press was printed. There remained prin- 
cipally the fossils of the Chalk formation, in the preparation of which, 
for the press, the present Editor has to acknowledge the prompt and 
friendly contributions, by William Lonsdale, Esq., F.G.S., of the de- 
scriptions of the Corals; by Professor Edward Forbes, F.R.S., of the 
Echinoderms ; by Professor Thomas Bell, Sec.R.S., of the Crustaceans ; 
by James De Carle Sowerby, Esq., F.G.S., of the Mollusks ; and the 
kind assistance rendered by Sir Philip de Malpas Grey Egerton, Bart., 
F.R.S., in revising the Author’s notes on the extinct fishes of the 
Chalk, and in describing the plates illustrative of that class of the 
Cretaceous fossils. 
Much expense had been incurred by Mr. Dixon in the illustrations 
of his Work, and after his decease, it was apprehended that its 
