128 



Table Contrasting Colour Varieties of Siphonogorgia variabilis. 



Siphonogorgia macrospiculata (Thom.son and Heuder.son) ( = Chironephthya 

 macrospiculata, Thomson and Henderson). 



'J'his outstanding species is at once distinguished by the large size of its 

 spicules. It is rejjresented by a single specimen attached to a piece of rock. 

 The basal portion is a stolon-like growth, extending over 2'6 cm. by Tfj cm., 

 from which there arise two separate stems 7 mm. apart. These curve out- 

 wards so as to form a V with convex sides. One of these, which is 2 '5 cm. 

 high and 0"9 cm. in diameter at the base, remains simple throughout its entire 

 length ; but the other, 2-7 cm. high and 0'9 cm. in diameter, divides into two equal 

 branches about 2 mm. from the basal portion. The outer branch again immedi- 

 ately gives off another lobe-like portion. 



The whole colony is markedly stiff and rigid owing to the presence of 

 large white spicules which curve upwards and present a singularly rough 

 surface. The interstices are filled up with smaller white and red spindles. 



The colour is a light brown, but the white granular-looking spicules give 

 the whole a streaky appearance. 



Polyps occur all over the colony but more closely packed near the tips of 

 the branches. They are borne on very distinct calyces which have a character- 

 istic structure. Three or four large spicules stand out from the general 

 coenenchyma at an acute angle. Between these and the main surface several 

 smaller spicules fill up the gaps, so that there results an almost semicircular 

 platform bounded on the other side by the cortical layer of the stem. Within 

 this the anthocodia can be retracted. 



