KüLLiKER (1865) uses the word Gorgonidse as a family designation, but as thus used 

 it embraced the whole of what is now known as the Gorgonacea. Tliis writer employs the 

 name "Gorgonacea" for a section of his subfamily "Gorgoninae", thus practically reversing the 

 relative rank of the names as we now know them. In his genus "Gorgonia" he includes 

 practically all of the species then known that would now go into the family Gorgonidae. The 

 first formal and adequate definition of the family was given by Studer in 1887 in his classic 

 work "Versuch eines Systemes der Alcyonaria" which is probably the most helpful single con- 

 tribution to our knowledge of the general systematic treatment of the Alcyonaria. His definition 

 will be adopted for our present purpose, and may be translated as follows : 



"Colony upright, branched, usually flabellate, with horny (rarely calcareous) axis. Polyps 

 bilaterally or biradially placed on stem and branches, corresponding to a biradiate arrangement 

 of the canal system. The upper part of the polyp is retractile either into an e.xserted calyx 

 or within the coenenchyma which presents a smooth surface. The spicules are small, preponder- 

 atingly spindles which are not arranged in two layers". 



The region explored by the Siboga Expedition is one in which the family Gorgonidae 

 is very poorly represented, and the collection contains so few species (five in all) that it does 

 not offer a basis for a systematic discussion. The writer will therefore content himself with 

 adopting, in the main, the excellent generic definitions of Studer, and will discuss only the 

 four genera represented in the collection. 



The paucity of representation of this family in this and other extensive collections in 

 the East Indies is remarkable when contrasted with the great number of Gorgonidae in the 

 West Indies and on the Pacific Coast of tropical America, and indicates very plainly that the 

 centre of distribution of the Gorgonidee is in the warmer waters of the Western Hemisphere. 



Synoptic view of the genera and species of GoRGONio.ii 

 collected by the Siboga Expedition. 



New species are indicated by an asterisk (*■). 



Lophogorgia. 



Lophogorgia * pinna ta. 



Leptogorgia. 



Leptogorgia "forinosa. 



Stenogorgia. 



Sicnogorgia in 171 lata, S. *sfnderi. 



Platycaulus. 



Platycanlns "sibogcc. 



The only previously known species in this list, Stenogorgia viiniata (Valenciennes) has 

 hitherto been known only from the Atlantic Ocean, where it has been taken in the West 

 Indies and Azores. 



