THOMSON AND MACKINNON — STOLONIFEEA, ETC. 193 



60. Siphonogorgia flavocapitata (Harrison). (Plate 9. figs. 10 & 12.) 

 See Harrison: Journ. Linn. Soc. (Zool.) xxx. 1908, p. 187. 



Two specimens wliich agree closely with this species as described by Miss Harrison. 

 We have been able to compare it with one of her preparations. 

 Localities. Providence, 50 fms. ; Amirante, 39 fms. 

 Previously recorded from Admiralty Islands. 



61. Siphonogorgia robusta, sp. n. (Plate 11. fig. 2; Plate 14. fig. 3.) 



Five intact specimens, from 4-8 cm. in height. There is also a fragment of stem, 

 including the basal portion, and three branched pieces from higher up. 



The basal attachment is narrow, flattened, and slightly encrusting. From it arises 

 the erect firm stalk, without branches for the first 3-4 cm. of its height. It is deeply 

 furrowed and has a very coarse, rough texture. The branches arise from all sides without 

 definite arrangement. They are markedly thick in proportion to their length (diameter, 

 4-5 mm. at junction with stem), and taper scarcely at aU. This tends to give the colony 

 a characteristically heavy, thick-set appearance. 



The polyps occur on the stem, upwards from the point at which the first branch 

 comes off, and on the branches, where they form a spiral. The spiral is closer in its 

 windings towards the end of the branch, where it finally terminates in a group of 3-4. 



The verrucse are more strongly developed on their outer edge, so that they form a 

 series of " graptolite "-like projections along the branch. The polyps are, in many 

 cases, wholly retracted into these. 



The arrangement of the spicules in the polyp-crown is very characteristic. There 

 are eight points, formed in each case of a pair of long, thorny spindles ; these are bent 

 outwards at the base, somewhat after the manner of a hockey-club. The straight 

 tapering " handles " of each pair lie closely apposed, while the space between their blunt, 

 diverging, curved ends may contain one or two small straight spindles. Similar small 

 spindles are inserted in parallel groups of 2-3 between each pair of " hockey-clubs " and 

 its neighbours. The tentacles are further heavily armoured with a double row of small 

 yellow spicules " en chevron." Below the " points " is a ring of horizontally arranged 

 spindles about six rows deep, and over the base of this project the ends of tlie spicules 

 that form the verruca into which the polyp is retractile. 



One is struck at once by the large size of the polyp-spicules ; their heavy build and 

 close setting give the polyp-head a massive appearance that is very characteristic. 



(1) The spicules of the coenenchyma are massive crimson spindles densely covered with 

 rather large tuberculate warts. The larger spindles are 2-21 X '42, 1-56 X '28, 1-19 X 

 "187 mm. in length and breadth, while the smaller ones are -74 X '068, '714 X '059 mm. 



(2) The "hockey-club" spicules of the anthocodial points are -85 x "136, '74 x 

 ■119 mm. Like the other spicules, they are covered with tuberculate warts; these 

 are most closely set over the blunt " club " end ; towards the " handle " they become 

 sparser and of much simpler form, finally giving place to short spines which are directed 

 towards the tip of the " handle." The colour is crimson, fading into yellow near the 

 " handle " end. 



