liv THE VOYAGE OF H.M.S. CHALLENGER. 



If a species which was collected by Dr. Doderlein in Japan should be included in 

 this genus, the generic diagnosis must be amended. In its general structure the form 

 in question agrees with Gray's description. It consists of a simple rod -like stem with a 

 horny axis. The cortex at the end of the stem is unfortunately wanting, so that it is 

 not possible to decide whether the form was club-shaped or not. The coenenchyma is 

 thin with a rough surface, on which the spine-like points of the spicules everywhere 

 project. The polyp calyces are disposed in thick spirals round the stem, and form 

 inconspicuous conical warts arising at right angles from it ; their oral apertures are 

 surrounded by a circlet of spicules. The opercular rays lie horizontally over the mouth. 

 The spicules in the coenenchyma form a deep layer of warty curved spindles, and above 

 this a laj^er of spinose discs, each with a smooth terminal apex and basal spiny processes, 

 the apices of which project all over from out of the coenenchyma, and they form around 

 the margin of each calyx a circlet of spines. 



10. Placogorgia, Wright and Studer, Archiv f Naturgesch., Jahrg. liii. Bd. i. 



p. 56. 



The colony is branched with a thick coenenchyma, and with low truncated conical 

 polyp calyces arising at right angles from the axis. The spicules on the calyces are 

 broad, warty discs, often with branched thorny and spiny processes, somewhat resembling 

 those of Paramuricea. The warty discs overlap one another on their margins. The 

 tentacular opercula lie horizontally, and consist each of three spicules, two lateral and 

 one median. They are not in contact by their lateral margins. 



11. Echinomuricea, Verrill, Proc. Essex Inst., vol. vi. p. 45 ; Amer. Journ. Sci. 



and Arts, vol. xlvii. p. 285, 1869. 



The colony is simple or branched; the stem and branches are thickly beset with the 

 polyp calyces. These are short, cylindrical or conical, truncated terminally, and with 

 horizontally disposed tentacular opercula. The calyces are covered with spicules of a 

 peculiar form overlapping one another ; these consist of long flat needles, which give 

 off several root-like processes from their expanded ends. The apices of the needles 

 project. 



12. Echinogorgia, KoUiker, Icones histiologicse, pt. ii. p. 136, 1865. 



The colony is branched. The polyp calyces, which arise on all sides from the stem 

 and branches, are small and wart-like. The tentacular opercula are but feebly developed, 

 forming low cones. The spicules are in part spiny spindles, and in part spiny clubs and 

 discs. 



