43 



on an average 0-80 nnn. in height and ()-7") unn. in breadth, and are })laeed at 

 an obtuse angle on the stalk which averages about 2 nun. in length. The spi- 

 cules are arranged in the following manner : At the base of the polyp there are 

 eight double I'ows of two to three pairs of converging spicules which meet at 

 an angle which varies from acute to obtuse ; above these there is a ring of 

 horizontally placed spicules, two to three deep, and above that rise eight double 

 rows of one pair of converging spicules 

 each. These double rows are a con- 

 tinuation of the lower double rows, and 

 in addition to the one pair one or two 

 other smaller spicules may be ])resent 

 which lie parallel to the larger si)icules. 

 The lower spicules average 4 mm. in 

 length and the upper spicules, which 

 project considerably, average 0'80 mm. 

 On the aboral surface of the tentacles 

 there are two rows of small, rod-like 

 spicules. 



The Stiitzbundel is not well de- 

 veloped, consisting of a few spicules 

 which average about U'9 mm. in length 

 and of which one may project for a very 

 short distance. 



Cortical spicules : (a) In the stem 

 there are curved or straight spindles of 

 various sizes with numerous closely placed 

 simple spines. The smallest average 



about 0"32 mm. in length, the middle about I'Z mm., and the largest about 

 I'S mm. 



{/)) In the stalk there are short spindles with rough branched spines and 

 often a small foliar expansion at one end, irregular spindles, and numerous 

 irregular star-shapes. 



Canal-wall spicules : {(/) In the stem are numerous small, tlat spindle- 

 to star-shaped forms with toothed edges; they average about 012 mm. in 

 length. 



(b) The spicules of the stalk are similar to the preceding. 



Colour— Stalk, stem and principal branches white to semi-transparent; 

 smaller branches white with yellowish twigs ; twigs yellowish-brown ; polyp- 

 stalks brown ; polyps whitish to colourless. 



Locality : Padaw Bay (Dr. Anderson). 



Fig. 24. D. padaveusis. 



