THE ALCYONARIA OF THE CAPE OF GOOD HOPE AND NATAL. 553 



The characteristics of this species are distinct and well marked. In several of its 

 features it seems to stand near Bellonella variabilis, Studer, and Nidcdia arctica, Dan. 

 It shows, however, obvious differences from both these species, as in the latter the 

 polyp-bearing part of the colony is slightly branched, whereas in Bellonella studeri the 

 polyps stand free and are separated by small intervals of coenenchyma. It also differs 

 from these species in the arrangement of the spicules. The arrangement of the spicules 

 iu the polyps of Bellonella studeri is somewhat similar to that of Nidalia (Bellonella) 

 rubra, Brundin, but in the general form and in the shape of the spicules, there are wide 

 differences. It differs from Bellonella rigida, Brundin, in having a much plumper form, 

 in the polyps being separated from one another by small intervals of coenenchyma, and 

 in other characteristics. 



One must here refer to the changes introduced by KUKENTHAL in the nomenclature 

 and systematic position of these and allied forms. KUKENTHAL regards GRAY'S genera 

 Bellonella and Nidalia as equivalent, and uses the name Nidalia. He is convinced 

 that two different genera are contained in the genus Nidalia (Bellonella), and that 

 some species belong to the family Alcyonidse, while others should be classed asNephthyidse. 

 Under the family Alcyonidse he constitutes a new sub-family, viz. the Nidalinae, of 

 which the most important characteristics are as follows : The colony is un branched ; 

 the upper part of the polyp can be withdrawn within a retractile calyx, and the gastral 

 cavities of the polyps stand in direct communication with one another. In this sub- 

 family he places two genera : Nidalia, Gray, em. Kiikenthal, and Nidaliopsis, Kiikenthal. 

 His diagnosis of the genus Nidalia is as follows : 



The colony is unbranched, rarely cleft, and consists of a sterile stalk and a sharply 

 differentiated conical or cylindrical polyp-bearing part. The upper part of the polyp is 

 soft-walled, and retractile within a non-retractile calyx. There is no dimorphism. 

 The polyps are generally continued to the base in wide gastral spaces containing 

 mesenteries. The communication between the polyps is partly direct by transverse 

 canals, partly indirect by an endodermal canal network. The spicules are mostly 

 thorny (" bedornte ") rods and spindles. 



KUKENTHAL holds that the following species belong to the genus Nidalia as emended 

 by him : Nidalia occidentalis, Gray ; N. granulata, Gray ; N. rubra, Brundin ; 

 N. cinerea, Brundin ; N. rigida, ( = Eleutherobia japonica, Putter) and N. indica, 

 Thomson and Henderson. Further, that the following do not belong to Nidalia but 

 to the genus Gersemia, Marenz, em. Kiikenthal : N. foliacea, Ung ; C. bocagei, Kent ; 

 C, studeri, v. Koch; Bellonella variabilis, Studer, and Nidalia arctica. More 

 recently he has removed Nidalia foliacea to the genus Capnella-. KUKENTHAL'S 

 diagnosis of the genus Gersemia, in his monograph on Japanese A Icijonaceen, 1906, 

 differs slightly from that contained in his Versuch einer Revision der Alcyonarien. 

 II. Die Familie der Nephthyiden, 1907. His later diagnosis is as follows: 

 " Nephthyiden ohne Stutzbiindel, die Polypen stehen nicht in Lappchen oder Biindeln, 

 sondern einzeln. Der Aufbau der Kolonien ist baumformig, doch konnen die Aeste 



