109 



Fig. 53. D. oohracea. 



nioasuring on an average 0'48 mm. in height and 0-72 mm. in breadth. They 

 stand at a right angle to the stalk, which measures up to 1-25 mm. in length. 

 The sj)icules are arranged in eight double rows in each of which there are five 

 to six i)airs of converging spicules ; the uppermost pair in each row is slightly 

 larger than the others and i)rojects a short dis- 

 tance beyond the polyp. The spicules are flat- 

 tened spindles, straight or curved, with few spines, 

 averaging 0'19 mm. in length, the uppermost pair 

 being up to 0"24 mm. long. There are a few large 

 spicules arranged irregularly at the base of each 

 polyp. On the aboral surface of each tentacle 

 there are two rows of small rod-like spicules 0'017 

 mm. long. 



The Stutzbimdel is well developed, and con- 

 sists of a nund;)er of spindles, several of which 

 may project beyond the ])olyp-head. They may 

 reach a length of 24 nun. and project OS mm. 



Cortical spicules : {(/) In the stem there are 

 large spindles, straight or curved, thickly covered 

 with simple to blunt spines, from 0'19 to 3"2 mm. 

 long, and from 0-048 to 0'4 nun. broad. 



(b) In the stalk there are short thick spindles, three-rayed, incipient 

 four-rayed, short, thick rods, and numerous smaller, irregular foi-ms. All are 

 thickly covered by blunt, rough warts. Spindles vary in length from 0-16 to 

 1-12 mm. and in breadth from 008 to 022 mm. In the four-rayed forms the 

 centre has an X-shaped mark, and in many cases two of the rays may be repre- 

 sented by mere stumps on the side. 



Canal-wall spicules : [a) In the stem there are long spindles similar to those 

 of the stem cortex but very few in number, varying from 0'8 to 24 mm. in 

 length and from 0'16 to 0'32 mm. in breadth. There are also a very few small, 

 flat rods with toothed edges. 



{/>) In the stalk there are thick spindles, three- and four rayed forms, 

 spindles with several l)ranches at one end, and spindles with two branches 

 arising together at the middle point of one side and running parallel and in 

 close contact throughout their length. All are thickly covered by blunt, rough 

 warts. The spindles vary in length from 0'64 to 1'6 mm. and in breadth from 

 010 to 032 mm. The rayed forms may reach a length of 12 mm. from tip to 

 tip, and may have a breadth of 032 mm. in a ray. 



Colour — Stalk yellowish-white ; stem and branches light orange ; twigs 

 light orange streaked with i-ed ; polyps white. 



Locality : Andamans (J. Wood-Mason). 



