PREFACE.
This volume is in large part a reprint of various popular descriptions and notices in the American Museum Journal and elsewhere by Professor Henry Fairfield Osborn, Mr.Barnum Brown, and the writer.

There has been a considerable demand for these articles which are now mostly out of print.

In reprinting it seemed best to combine and supplement them so as to make a consecutive and intelligible account of the Dinosaur collections in the Museum.

The original notices are quoted verbatim; for the remainder of the text the present writer is responsible.
Professor S.W.Williston of Chicago University has kindly contributed a chapter--all too brief--describing the first discoveries of dinosaurs in the Western formations that have since yielded so large a harvest.
The photographs of American Museum specimens are by Mr.A.E.

Anderson; the field photographs by various Museum expeditions; the restorations by Mr.Charles R.Knight.Most of these illustrations have been published elsewhere by Professor Osborn, Mr.Brown and others.