36 



and irregular four-rayed and rough star-shaped forms. They are all furnished 

 with large prominent thorns, simple or compound. There are also short, curved 

 spindles with huge thorns on the convex side, and irregular stars with few 

 spines. The spindles may reach a length of 24 mm. and a breadth of 015 mm. 

 The spicules are so arranged on the stalk as to produce a stringy appearance. 



Canal-wall spicules : {a) In the stem there are a few small curved spindles, 

 0"27 mm. long and 0024 mm. thick, and flat star- to spindle-shaped forms. 



(b) The stalk has spindles, straight or curved, and often showing bifurca- 

 tion at one end, three-rayed and a few four-rayed and irregular forms, some of 

 which might be called incipient clubs. The spindles measure up to 103 mm. 

 in length by 0"15 mm. in breadth. 



Colour — Stalk white ; stem yellowish-white marked with pink ; terminal 

 branches and twigs pinkish ; the polyps appear red owing to their spicule 

 colour. 



Locality : Andamans. 



Dendronephthya macrocaulis, Henderson. 



This species is based on two specimens, in the larger of which the stalk is 



absent, and in the smaller the stalk 

 is very short. The polyparium of 

 the larger measures about 6 cm. in 

 height and 6'5 cm. in gi'eatest 

 breadth. 



The stalk was apparently short 

 and had its upper portion hidden 

 by the rettexed lower branches. In 

 the smaller specimen it is granular 

 in appearance. 



The polyparium is markedly 

 flattened, irregular in outline and 

 very loose and open, and is char- 

 acterised by the enormously long 

 polyp-stalks, which average a little 

 over 5 mm. in length and often 

 reach 8 mm. It consists of a 

 number of principal branches each 

 of which gives oft' other large 

 branches which finally give rise to 

 the polyp-bearing twigs. The prin- 

 Fig. 21. D. macrocauUs. ^jp^j branches are flattened in the 



plane of the polyparium, and give off' from all sides small branches which 



