INTRODUCTION. 
PREFACE. 
The privilege and pleasure of studying the wonderfully rich collection of unstalked 
crinoids brought home by the "Siboga" I owe to the courtesy and generosity of my friend 
Professor Reni^- Koehler. While I was visiting him at Lyons in the summer of 1910 he showed 
me, among many interesting things, an extraordinary assemblage of comatulids from the East 
Indies, which he said he would be glad to turn over to me if I cared to study them. Naturally 
I hesitated at depriving him of the opportunity offered by this material for the elucidation of 
many obscure points in regard to the East Indian crinoid fauna, but with his characteristic 
unselfishness he insisted that I should undertake the work. 
Much of the satisfaction which I have derived from the present study has been due to 
the fact that my friend Professor Ludwig Doderlein prciiared the companion volume upon the 
stalked crinoids, and I have been keenly appreciative of the honour of being thus associated 
with him. 
SCOPE OF THE PRE.SENT WORK. 
In a recently published memoir entitled "Crinoids of the Indian Ocean" (Calcutta, 191 2) 
I brought together all the information regarding the crinoids of the Indo-Pacific region, and 
included an historical introduction and a complete bibliography. The present work is essentially 
a refinement of the preceding. Every family, genus and species has been ree.xamined, and new 
keys have been prepared for all of the subfamilies, genera and species. In spite of the great 
amount of new material, relatively few changes have been found necessary, and these changes 
fall chiefly in the very difficult family Antedonidae. 
Ivvcry comatulid genus is mentioned, though the extralimital are as a rule not treated 
in detail. It has seemed advisable, however, to include keys to the species of the genus 
AntcdoH of the middle and northeastern Adantic, of Lcptometra of the east and northeast 
Atlantic, of Coccometra of the Caribbean region and of Floromctra of the east and north 
Pacific in order to emphasize their .similarity, and the similarity of their internal interrelationships, 
to the corresponding PLast Indian types, Mastigometra and Eiiantedon, Psathyrometra, Thysano- 
metra and Cyclonietra. 
