Simpson — A Revision of the Gorgonellidae. 3 



too, appears to afford littlfe help in the determination of species. The 

 form, size, and distribution of the zooid-verrucae, and the proportions of 

 the corallum as a whole, seem to be the best points to rely upon. Jiincdla 

 dongata, however, seems to be distinct in spiculation." 



In reporting on the Littoral Alcyonaria of the Indian Ocean (Thomson 

 and Simpson, 1909), we drew up a comparative table of all the specimens in 

 this group which could not with certainty be referred to unquestionable 

 species. 



These ■ specimens, along with those of other collections on which 

 Prof. Thomson has reported, have been kindly handed to me as a basis for 

 this memoir. 



Since 1905, however, it has been my privilege to do some biological work 

 on board the Royal Indian Marine Survey ship " Investigator " ; and during 

 that time I had an opportunity of collecting and observing a very large 

 number of specimens belonging to this group in the waters around the 

 Mergui Archipelago — a happy hunting-ground for .luncolHil.s. By this 

 means an extended study of variability was rendered practicable in a way 

 which would otherwise have been impossible ; and this has been of immense 

 value in generic and specific determination. 



The writer has also been fortunate in visiting a number of museums in 

 which old specimens are deposited, and there examining these forms ; 

 while others, more inaccessible, have been kindly lent for examination. 



The following list gives the more important collections in which 

 specimens of this group occur, uU of which have been systematically 

 examined in the preparation of this report. 



II.— Material examined fou this Me.moih. 



1. The Hunterian Collection of Gorgonellids in the Museum of the Eoyal 

 College of Surgeons, London. This is a very old collection, and contains 

 many interesting specimens which were of great use in determining the 

 nature of the spiculation in some of the older species whose descriplion.s 

 dealt entirely with macroscopical characters. 



2. The Gorgonellid specimens in the collection of the Natural History 

 Section of the British Museum, which include (1) mo-st of the specimens on 

 which the voluminous work of Gray was based, (2) the specimens of the 

 " Alert " collections, and (3) the type-specimens of the " Cliallenger " 

 expedition. 



?j. The collection made by Professor Heninian in tiie Ceylon seas (1902), 



described in tiie Ceylon Pearl Oyster Keport (Koy. Soc), and now deposited 



in the British Museum. 



B2 



