CONTENTS 



PAGE 



INTRODUCTION , 



Preparation and Scope j 



Collections 2 



Collectors , , 



Illustrations j - 



Acknowledgments t g 



TERMINOLOGY lQ 



Explanation of Terms 20 



MORPHOLOGY 24 



A. The Primary Plates 27 



I. Abactinal System 2 y 



a. The Column 2 y 



b. Inf rabasals and Basals 3! 



c. Radials and Brachials 4I 



d. The Arms 45 



II. The Actinal System 48 



a. The Tegmen 48 



B. The Supplementary Plates 52 



a. Interradials and Interbrachials 52 



b. The Anal Structures 56 



INTERRELATIONSHIPS OF THE FLEXIBILIA 60 



NEW RESEARCHES 79 



On the Ontogeny of Some Recent Crinoids bearing upon the Phylogeny of the Flexibilia 79 



PHYLOGENETIC RELATIONS 88 



DISTRIBUTION 93 



I. Biologic by Families 93 



II. Geologic by Families 93 



III. Geographic and Geologic by Genera 94 



IV. Geologic by Species 99 



CLASSIFICATION 100 



Primary Divisions of the Crinoidea 105 



Order FLEXIBILIA 112 



The Families of the Flexibilia 120 



List of the Genera 121 



SYSTEMATIC PART 



LECANOCRINIDAR 122 



Analysis of the Genera 122 



Geological and Geographical Distribution 124 



Lecanocrinus 125 



Homalocrinus 144 



Calpiocrinus 145 



Anisocrinus '■ 160 



Hormocrinus 166 



Cholocrinus 170 



Asaphocrinus 174 



Pycnosaccus 180 



Mespilocrin us 190 



Nipterocrlnus 201 



