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 René 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 prepared 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 PRESENT 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 reëxamined, and nevv 

 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. 



Every 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 

 Antaion of the middle and northeastern Atlantic, of Leptometra of the east and northeast 

 Atlantic, of Coccometra of the Caribbean region and of Florometra of the east and north 

 Pacific in order to emphasize their similarity, and the similarity of their internal interrelationships, 

 to the corresponding East Indian types, Mastigometra and Etiantedoti, Psathyro??ietra, Thysano- 

 metra and Cyclometra. 





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