REPORT ON THE ALCYONARIA. XXXV 



I. Suherogorgia, Gray, Proc. Zool. Soc. Lond., 1857, p. 159. 

 Sderogorgia, Kdlliker, Icones histiologicae, pt. ii. pp. 142, 144, 1865. 



The colonies are upright, branched, the branches sometimes anastomosing. Polyps 

 with slightly protruding calyces, which are especially distributed on either side of 

 the somewhat flattened stems and branches. The coenenchyma is thick, and exhibits 

 longitudinal furrows on the surface of the areas which are free from polyps. The 

 spicules are warty spindles, and in one species birotate. 



2. Keroeides, Wright and Studer, Archiv f. Naturgesch., Jahrg. liii. Bd. 1, p. 30. 



The upright colony branches in one plane ; the polyps form wart-like verrucse, which 

 are given off mainly from two sides of the somewhat flattened branches, leaving an 

 interspace free. The spicules of the coenenchyma are large broad spindles and poly- 

 gonal, often triangular discs. These latter are closely approximated to one another, 

 and form a pavement-like outer layer in the coenenchyma. The calyces are thickly 

 covered with polygonal scales, and the tentacles also contain broad smooth spicules. 

 The whole habit, and even the character of the spicules, recall the genus Acis. 



The axis is colourless and consists of closely intercalated calcareous spindles enclosed 

 in a horny filjrous substance, which remains and preserves the form of the axis after 

 decalcification. 



Family III. M E L i T o d r d .^. 



MeJifhxidx, Ridley, Rep. Zool. Coll. H.M.S. "Alert," Alcyonaria, p. .3.56. 

 Mditheeareee, Kollfker, Icones histiologies, pt. ii. p. 142. 



Melitheeadx, MopseUadx, TrinelJwise, EUiselladx (p"rs), Gray, Cat. Lithophvtes Brit. Mus. 

 pp. 3, 5, 12, 24. 



Scleraxonia with a well-marked axis, which is jointed, i.e., consisting of alternatino 

 portions of a hard calcareous and of a soft horny substance. The hard joints [inter node.H) 

 consist of fused calcareous spicules, with but a trace of horny .substance ; the soft joints 

 (nodes) are formed of loose calcareous spicules, in a mesh of lioruy substance. 



Gray made of this group a number of distinct families, l)ut these, as Ridlev has 

 shown, ^ cannot be upheld. Ridley proved that the difference on which Gray relied in 

 distinguishing Melithaeidse and MopseUadse, namely, the penetration of the axis b\- 

 nutritive canals, is not persistent, and he refers the genera to one family, and 

 distinguishes them only by the characters of their spicules. The Melitodidse may be 

 po.ssibly derived from the Briareidse. Like the lower forms of the latter many Melitodidai 

 exhibit nutritive canals within the axis. Ridley thinks that siphonozooids may occur 

 as in Parogorgia beside the autozooids. An example of this dimorphism, he thinks, is 



' Loc. cit., p. 356. 



