231 



other Alcyonaria {Solenocatdoii). They are branched in one plane and anas- 

 tomose freely to form a, wide meshed network. Typical colonies measure 100 

 mm. X 100 mm., 120 mm. x 110 mm., and 120 mm. x 100 mm. The last 

 mentioned may be taken as the type. From a spreading base the short main 

 stem rises to a height of 27 mm., with a diameter at the base of 2-25 mm. 

 Three large branches are given off on one side and one on the other, but two 

 smaller ones have become detached. Three of these four constitute the main 

 support of the colony and ascend almost to the very top. From them smaller 

 branches arise, some running sub-parallel with the main branches, othei's run- 

 ning almost horizontally and fusing with their neighbours. 



The c(i?nenchyma is very thin so that the colour of the axis gives its colour 

 to the colony. With a low power the crjenenchyma presents a very prickly 

 appearance due to the spiny nature of the spicules. 



Polyps occur all over the surface of the coenenchyma. They are separated 

 by distances of 1 mm. to 2 mm., but are closer on the smaller twigs. The verrucse 

 are cylindrical in shape and measure 0'5 mm. in height and 0'5 mm. in diameter. 

 They are white in colour and very spiny. The spicules are arranged in eight 

 indefinite groups with eight projecting triangular-shaped teeth around the 

 circular opening. The anthocodire are almost completely retractile. The 

 tentacular operculum is very feebly developed and is horizontally disposed. 

 At the base of the "points " there is a hint of a circlet of curved spindles. 



The axis is horny and cylindrical with a cavity in the centre. The colour 

 varies from brownish-black near the base to pale yellow in the twigs. 



A very remarkable feature about the colony is the tendency to growth 

 in the axial portion. There are thin foliaceous expansions in several parts, 

 especially in the angles at the origin of the branches. Over the whole colony 

 there are very abundant small cirripede galls and worm-tubes, all enclosed 

 within a membranous expansion of the axis and overgrown with cojnenchyma. 



The spicules present the following types, with measurements length by 

 breadth in millimetres : — 



(1) A short, smooth or slightly warty spine proceeding from a branched 

 almost foliaceous base : — 



0-425 x-0-2, length of spine only 0-05 

 0-35 X 0-15, „ „ 005 



0-31 X 0-15, „ „ 0-03 



0-3 xO-2, „ „ 0025 



0-3 X 0125, „ „ 0025 



(2) Bent spindles warted on both concave and convex sides at the middle 

 of the bend, 02 x 005 ; 022 x 005. 



(3) Scale-like with smooth surface and irregular edges, 0'35 x O'l ; 0'32 x 

 0-25 ; 0-3 X 0-2 ; 025 x 0-2. 



