THOMSON AND MACKINNON— STOLONIFEKA, ETC. 189 



55. Siplionogorgia mirahilis, Klunzinger. 



For description see : — 



Klunzinger : Koralltliicrc des Rothen Meeres, 187", p. 49, }d1. 3. fig. 9. 



Hickson : Alcyoiiaria of the Maldives, pt. i. (1903), in Fauna and Geography of the Maldive and 

 Laccadive Archipelagoes, vol. ii. pt. i. p. 492, pi. 26. figs. 11 & 12. 



Numerous brancIiiDg- pieces of colonies, 3-5 cm. in length, all agree very closely with 

 KluDzinger's description of this species, but the spicules seem larger. Klunzinger's 

 measurements are, for the larger spicules •5X"128 mm., and for the smaller ■11-12 X 

 ■016 mm. ; whereas in our specimens 1^1 X '18 mm. is a common measurement. Some 

 spicules attain the proportions 1-36 X 2 mm., and only the smaller spicules are ■SSx 

 •15 mm. and ■SOxl? mm. 



Eive fragments are dull red with lemon-yellow polyps, as described by Klunzinger ; 

 all the others have white polyps. 



The polyp-armature consists of a crown and points. Each point is formed of from 

 six to eight curved slender spindles. These may lie almost parallel to one another 

 within the group, or may even diverge a little distally, thus agreeing with Hickson's 

 figure, where he shows the " fan " arrangement to be characteristic of S. mirabllis. 

 Much more frequently we found that the spicules tend to leave the parallel arrange- 

 ment, and come to be divided into two groups, which converge to form the " point." 

 This agrees with Klunzinger's figures and seems to be the more usual arrangement. 

 Below the points the horizontal band of similar spicules is about 8 or 10 rows deep. 

 It is surrounded at the base by the ends of the supporting spicules of the coenenchyma, 

 which, in the second set of specimens, show a tendency to form an 8-pointed verruca. 



Locality. Providence, 50-78 fms. 



Previously recorded from the Red Sea, the Maldives, and Teimate, 30 fms. 



56. Siphonogorgia hicksoni, sp. n. (Plate 11. fig. 3 ; Plate 14. fig. 4.) 



Pive more or less complete specimens, varying in height from 8-3^5 cm. There is a 

 slightly encrusting basal attachment. Prom this arises an erect trunk, continued for 

 some 2-4 cm. before any branching occurs. It is cylindrical at first, with a diameter of 

 from 4-7 mm., but becomes compressed and deeply furrowed from the point where the 

 branches begin to come off. 



The branches arise for the most part without any definite arrangement, though in a 

 few cases the branching is confined to one plane. They tend to be broad and flattened, 

 especially near their junction with the main stem, and are often pendtilous at the tips. 

 Secondary branches occur rarely. 



The branches alone bear the polyps, which are arranged in wide spirals, ending at the 

 tip of the branch in a group of 3-4. The polyps are unretracted, and project distinctly. 

 The verrucsB, wliich support them, are more strongly developed on the side away from 

 the branch, so that the polyps face directly up towards the tip. 



Their armature is a " crown " with points formed of eight groups, each consisting of 

 3-4 short red spindles ; these lie more or less parallel to one another, but occasionally 

 one spicule may dominate, or two may converge, so that the effect of a " point " is 



25* 



