99 



Hat or slightly concave ui)i)er surface to the groui). They measure 0'4 mm. in 

 height and 0'.32 to 072 mm. in breadth and are placeil at a very obtuse angle 

 on stalks which measure up to 0'8 mm. in certain cases. The spicules are 

 arranged in eight double rows in each of which there are five to seven 

 pairs of converging flat spindles, about 03 mm. in length and 003 mm. in 

 breadth. 



The Stiitzbiindel is not well developed except in a few of the polyps in 

 each group. It forms in the majority of cases a sheath for the stalk, and con- 

 sists of a number of spicules which average about 1 mm. in length and project 

 0'24 mm. beyond the polyp. In the other cases one or more of the spicules 

 may reach a length of '2-i mm. and may project 09 mm. beyond the 

 polyp. 



Cortical spicules : (a) In the stem the spicules are long, slender, straight 

 or curved spindles with numerous smooth spiny processes, and a few flat, 

 smooth, striated stars and rods. The spindles vary in length from 0'35 to 2-1 

 mm. and in breadth from 003 to 010 mm. The flattened forms may reach a 

 length of 012 mm. In the stem and branches the spicules are arranged moi'e 

 or less transversely, but in the smaller twigs they tend to run parallel to the 

 length of the twig. 



{/j) In the stalk the spicules are spindles, clubs, three- and four-rayed forms, 

 all covered with numerous simple, sharp spines. The spindles vary from 0'32 

 to 1"6 mm. in length and from 008 to O'l mm. in breadth, the clubs are 07 mm. 

 long and 013 mm. broad, and the three- and four-rayed vary from 0<i4 to 0"8 

 mm. in length from tip to tip. 



Canal-wall spicules : (a) In the stem the spicules are long, slender, straight 

 or curved spindles with few small, smooth spines on the surface, and in addition 

 a few small flat rods. The spindles vary in length from 04 to 16 mm. and in 

 breadth from 0-03 to 0'08 mm., the flattened rods varying from 0'08 to 0'24 nun. 

 in length and from O'Ol to 003 mm. in breadth. 



(b) In the stalk the spicules are straight or curved spindles and three-rayed 

 forms, all with simple spines on the surface, and a very few smooth, flat rods. 

 The spindles vary from 032 to 06 mm. in length and from 006 to 009 nun. in 

 breadth, and the three-rayed forms measure from 08 to 09 nun. from tip 

 to tip. 



Colour — The stalk is white to translucent ; the stem and branches white ; 

 the twigs white on the lower, pinkish-white on the upper part of the polyparium ; 

 the polyps dark red in the lower, paler in the upper part of the polyparium ; 

 the tentacles whitish to translucent. In several parts the polyp-spicules are 

 not red, so that the whole polyp is of a white colour. 



Locality : Andamans (G. H. Booley). 



