THE ALCYONARIA OF THE CAPE OF GOOD HOPE AND NATAL. 565 



me also that the species from the Cape named Alcyonium antarcticum by Hickson is 

 not rightly so designated. The description and figures given by Hickson do not 

 sufficiently agree with the description and figures given in the Challenger Report, and 

 Professor Studer also regards Hickson's Alcyonium antarcticum as a mistake. More 

 recently I have had the opportunity of examining Hickson's type specimens. At first 

 1 thought that the species under consideration was probably Metalcyonium capitatum, 

 Pfeffer. Pfeffer says : " Der Poly penstock hat das Aussehen eines jungen Pilzes, 

 d.h. er ist kurz gestielt mit dickem Kopfe, oder der Stiel ist ganz verschwunden und 

 der ganze Stock stellt ein kopfartiges Gebilde dar." 



This resemblance between the two species appears to be mostly a superficial one, for 

 Metalcyonium capitatum shows the following features which separate it from my form : — 



(1) It appears to be frequently flattened in form ; (2) the polyp-bearing part is not 

 sharply separated from the so-called sterile part ; (3) the calyx is not very clearly 

 defined; (4) a transverse ring of spicules below the tentacles does not occur; (5) the 

 stomodseal tube has no spicules; (6) the polyps appear to stand much nearer one 

 another. 



Metalcyonium clavatum, Pfeffer, has the following characters distinguishing it 

 from my species : — 



(1) It has no sharp distinction into trunk and head ; (2) the polyps are not sharply 

 differentiated into retractile part and calyx ; (3) the stomodseum is free from spicules ; 

 (4) several colonies frequently appear to originate from a common base. 



Metalcyonium patagonicum has been described by May and Kukenthal. The 

 specimens are described as club-shaped. The spicules of the polyps appear to agree in 

 the main with those of my specimens. My specimens are considerably larger. In 

 both, there is a gradual passage from the membranous base into the trunk. The polyps 

 in my specimens do not stand closer to one another above than below. The spicules of 

 the tentacles in my specimens are much larger. There is no mention of spicules being 

 present in the stomodseal canal of May's specimens. 



We thus see that there are a number of differences ; but some of these are probably 

 more apparent than real, due on the one hand to incomplete description, on the other 

 to variation, for this is one of those species which seem to vary very considerably. 



In regard to the specimens described by Hickson from South Africa under the name 

 Alcyonium antarcticum, we may note that his colonies were procured from ground of 

 a different nature. He gives a figure of a specimen which rather differs from my 

 larger examples, but resembles some of the younger forms in my collection. As 

 Kukenthal suggests, Hickson's specimens were probably young forms. The relative 

 size of the polyps in Hickson's specimens appears to be greater than in my forms. 



Kukenthal has divided the genus Alcyonium into three sub-genera, namely : (l) 

 Alcyonium, s. str., (2) Metalcyonium, Pfeffer, (3) Erythropodium, Kblliker. 

 Whether this classification is a good one or not, will be seen after further systematic 

 work has been done on this genus. 



TRANS. ROY. SOC. EDIN., VOL. XLVII. PART III. (NO. 19). 83 



