196 



sinuous. There is no hint of anastomosis. The axis is horny and dark brown 

 at the base, but becomes almost pale yellow in the twigs. The diameter of the 

 main stem is over 4 mm., that of the twigs about 1 mm. The coenenchyma is 

 thin and allows the axis to shine through. It is densely covered by an 

 armature of warty spindles which are easily rubbed of. 



On the main stem and larger branches the polyps occur all round at con- 

 siderable intervals, but on the twigs they are disposed mainly on the lateral 

 surfaces. When expanded the verructe are cylindrical and are about 3 mm. in 

 height and 1 mm. in diameter ; they are capable of retraction to a height of 1 

 nmi. On the verrucas the spicules overlap and form a network which is sur- 

 mounted by eight triangular teeth, each composed of two spicules enclosing an 

 acute angle. Abundant spicules are found on the aboral surface of the tentacles. 



The spicules are predominantly spindles. The following are some of the 

 measurements length by breadth in millimetres : — 



(a) Ccenenchyma : Warty spindles, 0-9 x 0-2 ; 0-8 x OlS ; 0-G x U- 1 ; 



0-4 X 0-08. 



{b) Tentacles : Spiny spindles, 0-4 x 0-02.3 ; O'S x 0-03 ; 02 x 0-025 ; 



0-2 x 0015. 



Another- specimen in the Wood-Mason Collection is 150 mm. in height 

 and 90 mm. in maximum bi'eadth. The basal attachment is conical and much 

 expanded. The branching is in one plane and anastomosis does not occur. 

 The stem is 2 mm. in diameter at the base and the main branches are about the 

 same. The height of the verructe is from 2-2-5 mm. The colour of the verructe 

 is creamy-white, that of the axis yellowish. This species may be distinguished 

 from A. verrilli, Thomson and Henderson, in the following respects : (1) The 

 whole colony is more robust ; (2) the branching is more profuse and more 

 strictly in one plane ; (3) the coenenchyma is thicker and more rugose ; (4) the 

 polyps are more numerous ; (5) the spicules are shorter and thicker ; (6) the 

 spicules on the tentacles are longer. 



From A. (jlomeratn it differs markedly in the disposition of the verrucas. 



Locality : Andamans. 



GENUS CALICOGORGIA, Thomson and Henderson. 



Calicogorgia investigatoris, Thomson and Henderson. 



To this species we refer a magnificent colony 235 mm. in height and 205 

 mm. in maximum breadth. It consists of a main stem arising from a conically 

 expanded base from which large branches are given off on either side ; these 

 again ramify in the same plane. The verrucas are truncated cones slightly com- 

 pressed, having a basal diameter of over 2 mm. and an average height of 3 mm., 

 the dome-like anthocodia^ standing on the top to a height of 1-5 mm. They 



