71 



Acamptogorgia bebrycoides, von Koch, var. robusta, n. Plate IIT. 



figs. 7 and 8. 



The colony is branched in one plane, most of the branches being given oil' 

 at one side. The tips of the twigs are somewhat club-shaped, and occupied by 

 three polyps. The general coenenchyma is rough in appearance. There is no 

 trace of a basal attachment. 



The axis is horny, yellowish in colour, and marked by a number of longi- 

 tudinal striae. The centre is composed of chambers separated from one another by 

 transverse walls, and containing a whitish substance which gives little or no trace 

 of effervescence when treated with acid. The cavity is not quite central, but lies 

 sometimes nearer one side, sometimes nearer the other. 



The polyps occur all over the surface of the main stem or branch. The 

 verrucae are almost cylindrical, but somewhat squat, 1'5 mm. in height, with 

 a basal diameter of 1-3-17 mm. A number of spines project round the 

 apex. 



The retracted anthocodiae bear an almost hidden low conical eight-rayed 

 operculum, which is formed by the infolded tentacles. The spicules on the 

 anthocodiae are arranged in a crown and points ; the crown consists of 2-3 trans- 

 verse rows ; the points have their spicules en chevron, with a number of short, 

 curved spicules at the base of each triangle. 



The ccenenchyma is thick, and has an arenaceous appearance. 



The spicules of the anthocodise are spindles, straight or curved, and COY. 

 by warty projections. Several are thickened at one end, and present a club- 

 shaped appearance. The following measurements were taken of length and 

 breadth in millimetres : 



0-6x0-1; 0-45x0-04; 0'2xO-03; 0'15x0'02. 



The spicules of the general ccenenchyma and of the verrucae are (l) spindles, 

 straight or curved, with warty projections, or with large, thorn-like projections 

 covered by warts ; (2) incipient quadriradiate forms ; and (3) irregular forms, 

 with two or three rays at one end. Their dimensions, taken as above, are : 



1. Spindles, 0-6x0-046; 0'5x0'04; 0'45x0'04. 



2. Quadriradiate forms, 0-4x0-25 ; 0'3x0'2. 



3. Irregular forms, 0-4x0-2; 0'3x0'2. 



The last kind of spicule is extremely irregular ; some seem to be almost Hat, 

 with large processes extending from the edges; others seem to be plates, with 

 spines projecting from them. 



Locality : Station 333 ; 6 31' N., 79 38' 45" E. ; 401 fathoms. 



