113 



inconspicuous spines; they vary from 0-32 to 14 mm. in length and from 

 0():32 to 016 mm. in breadth. 



(/>) Those of the stalk are similar to those of the stalk cortex. 



Colour — Stalk pure white ; stem and main branches yellowish-white 

 streaked with red, gradually becoming deeper red ; secondary and smaller 

 branches and twigs bright coral-red ; polyps pure white. 



Locality : Andamans. 



Dendronephthya agaricoides, Henderson. 



This specimen is characterised by its i)eculiar plate-like appearance and the 

 arrangement of its branches. Its total height is 1"5 cm. 



The stalk, about 1 cm. long, is thick, much ridged and wrinkled, and has 

 had a broad flat base of attachment. 



The polyparium is flat and spreading, and may be compared to a plate 

 longer than it is broad. The upper end of the stalk expands and grows in a 

 horizontal instead of in a vertical direction, thus 

 producing a thin, narrow, rod-like expansion on 

 the ends and lateral edges of which there is a 

 fringe of branches. In addition to four lower 

 flattened branches there are only four others, 

 also Hat, and a few small ones that arise from 

 the upper surface of the lower branches. The 

 latter nearly surround the upper portion of the 

 stalk, leaving only small free spaces between 

 them, and are flattened, leaf-like structures. 

 The other branches are slightly flattened. iVfter 

 repeated divisions the polyp-twigs arise. 



The polyps are arranged in bundles of seven 

 to nine, sevei'al of which may be grouped to- 

 gether to form a larger bundle. The polyps of 

 each group stand compactly together, causing 

 the bundles to assume a club-shape. On the 

 much-cut-up edges of the flattened branches, the polyps occur singly, or in 

 small groups on widely divergent stalks. They measure about 0-66 mm. in 

 height and about 072 mm. in breadth, and are placed for the most part at right 

 angles to the stalk, but this is varied from acute to obtuse according to position 

 in the bundle. The stalks, especially on the lower part, may reach over 2 mm. 

 in length, but the average is much shorter. The spicules are arranged in eight 

 double rows in each of which there are six to seven pairs of converging spicules ; 



one of the uppermost pair may be much larger than the others and may pro- 

 15 



Fig. 56. 



D. agaricoides. 



