CONTENTS. 



Page. 



Foreword, by H. F. Osborn xm 



Work op John Bell Hatcher, by H. F. Osborn xvir 



Editor's preface xxvn 



Author's preface xxix 



Part I. History of Discovery, Classification, Osteology, and Systematic Descriptions, 



by j. B. Hatcher. 



Chapter I. History of the discovery of remains of the Ceratopsia 3 



First discovery, by Dr. F. V. Hayden 3 



Discovery of type of Agathaumas sylvestris by Prof. F. B . Meelc 4 



Ceratopsia remains discovered in Colorado by Prof. E. D. Cope 5 



Discoveries by Dr. G. M. Dawson in Canada 5 



Explorations in Judith River beds by Professor Cope 5 



Remains of Ceratopsia discovered by G. L. Cannon, G. H. Eldridge, and Whitman Cross 6 



Discovery of well-preserved remains of Ceratopsia in Converse County, Wyo 7 



Discovery of Ceratopsia remains in Canada by L. M. Lambe 9 



Ceratopsia remains discovered in the Laramie of Montana by Barnum Brown and R. S. Lull 9 



Chapter II. Classification and representation of the Ceratopsia 10 



Classification of the Ceratopsia 10 



Alphabetical list of genera and species 11 



' Supposed European representatives of the Ceratopsia 12 



Chapter III. Osteology of the Ceratopsia 14 



The skull 14 



The cranium 15 



The occipital segment 15 



The sphenoidal segment 17 



The frill or parietal crest 19 



The quadratojugal arch 22 



The frontal region 24 



The nasals 25 



The maxillaries 25 



The transverse bones 26 



The pterygoids 26 



The palatines 27 



The vomer 28 



The premaxillaries - 30 



The cranial armature 31 



The supraorbital horn cores 32 



The nasal horn core 32 



The rostral bone 33 



The epijugals 34 



The epoccipitals 34 



External openings in the cranium 34 



The supratemporal fossae 34 



The postfrontal foramen 35 



The lateral temporal fossae .35 



The orbits 35 



The anterior nares - , 36 



The posterior nasal opening 36 



The posterior palatine vacuities - 36 



The anterior palatine foramina 36 



The brain and brain cavity 36 



The sense organs 38 



v 



