INTRODUCTION. 



This memoir contains a description of a rich collection of Littoral Alcyonarians 

 made by the Royal Indian Marine Survey Ship " Investigator " in the Indian 

 Ocean/ It is a continuation of a previous memoir (Thomson and Henderson, 

 1906) dealing with the Deep-Sea forms. 



The collection includes 187 species (sixty-one belonging to Dendronephtliya 

 or Spongodes); 108 are new, but fifty-three of these belong to Dendi'oneplithfia 

 or Spongodes to which additions continue to be made in embarrassing numliers. 

 It has been found necessary to establish four new genera, — Studerioteii appended 

 to the Alcyoniidic, Dacttilonepliihiin appended to the Nephthyidtt, Cactogorgia 

 among Siphonogorgiidai, and Paralwlemnou among the Veretillida;." 



The following table will show the general nature of the collection and the 

 distribution of the new forms : — 



1 1 wish to thank the Trustees of the Indian Museum for giving me the opportunity of 

 studying this fine collection of beautiful forms, and my thanks are also due to Professor A. Alcock, 

 LL.D., F.E.S., formerly Superintendent of the Indian Museum, and to Dr. Nelson Annandale 

 now Superintendent, for their kind assistance in connection with this prolonged and laborious 

 investigation. Prof. Gilbert C. Bourne was good enough to send me a number of specimens 

 belonging to the first " Investigator " collection and a report on these has been included. Through 

 the Carnegie Trust I was able to secure the help of Mr. J. .1. Simpson, joint author of this memoir, 

 whose indefatigable work in this connection was done during his tenure of a Carnegie Scholarship 

 and Fellowship. In the same way I have been able to include a report on the genus Dcndrone- 

 phthya or Sjwnijodes by Dr. W. D. Henderson, who worked at the puzzhng problem of its species 

 during part of the time of his tenure of a Carnegie Fellowship. I have to thank the Carnegie 

 Trustees also for a grant which has defrayed the expense of drawing four of the plates, and the ex- 

 pense of having zinc-blocks made for the text-illustrations. It would be ungrateful not to express 

 indebtedness to the artist, Mr. George Davidson, for his skill and patience. The engraver, 

 Mr. Edwin Wilson, also deserves to be congratulated on the success of his plates, for the coloured 

 ones in particular presented difficulties which have been happily overcome. — J. A. T. 



- Two of these genera have been previously reported and are here referred to as Studeriotes 

 (= Studeria, Thomson) and Gactorjoryia, Simpson. For the same reason all the numerous new 

 species of Dendronephlhya (or Spongodes) bear the name of Henderson. 



