482 Dr. J. S. Thomson on living Gorgonias 



Tlie internal structure and development of the two forms is 

 .alike. The two forms are sexuallj mature at the same time. 

 The two forms show variations, but during the young stages 

 thev are essentially in agreement. 



One may slightly extend von Kocli^s characters for 

 Gorgonia verrucosa so as to include Gorgonia cavoUni as 

 follows :— The ground-colour is white or red, the polyps 

 yellow, brown, or reddish. The axis is dark, almost black, 

 and scarcely visible through the rind. The surface of the 

 rind appears smootli when magnified ten times. The 

 branching may be irregular, but is frequently in one plane. 

 The branches frequently tend to lie parallel to one another 

 and perpendicular to the basal plane of attachment. The 

 relative size of the stem and branches is variable, frequently 

 no great difference between them. 



The spicules of the rind and verrucse are clubs and 

 spindles arranged in two layers j the clubs of the external 

 layer stand very close to one another and with their 

 principal axes perpendicular to the surface. The spicules 

 are transparent. 



The polyps are retractile, and there are usually seven or 

 eight small, needle-like spicules at the base of eacli tentacle. 

 The polyps are scattered over the surface of the coenenchyma, 

 but sometimes show a tendency on the smallest branches 

 towards an arrangement in rows. 



The verrucse have the form of low warts, with 5-8, 

 usually 5, marginal lobes. 



Yellow or red cells occur in the ectoderm of the tentacles. 



I would therefore suggest that one should retain the older 

 specific name verrucosa and abandon that of cavoUni, but 

 that the species verrucosa bo recognized as including two 

 varieties — red and white. It is also to be noted that these 

 two forms^ verrucosa and cavoUni, are now frequently referred 

 to the genus Eunicella. 



In 1869 Verrill constituted the new genus Eunicella, taking 

 Gorgonia verrucosa, Pall., as his generic type, and regarded 

 it as belonging to the family Plexauridse. Verrill's diagnosis 

 of the genus Eunicella is as follows : — 



" Coenenchyma thin or moderately thick, composed chiefly 

 of small warty double spindles, but having a distinct external 

 layer of very small, peculiar club-shaped spicules perpendi- 

 cular to the surface, which often have one or two whorls of 

 fine spindles towards the larger end. Cells scattered, either 

 raised on prominent verrucse or perfectly flat. Longitudinal 

 ducts nearly equal, in a circle around the axis. The colour 

 usually white." 



