REPORT ON THE ALCYONARIA. O 



As far as our present knowledge extends, the species of the genus Siphonogorgia are 

 confined to the Indo-Pacific region. The following species are those at present known: — 



Siphonogorgia squarrosa, Kolliker and Studer, . West Australia. 



„ pendula, n. sp., 



„ mirabilis, Klunzinger, 



kdllikeri, Wright and Studer, . 

 pustulosa, n. sp., 

 pallida, n. sp., 



Bay of Amboina. 

 ( Red Sea, Arafura Sea, 

 ( North-west Australia. 



Bay of Amboina. 



Off Api, New Hebrides. 



Admiralty Islands. 



godeffroyi, Kolliker, . . . Pelew Islands. 



Siphonogorgia pendula, n. sp. (PL I. figs, la, 16; PI. V. fig. 2). 



The stem is erect and branched, finally dividing into thin twigs, which are less rigid 

 than the larger ones, and bend towards the base of the stem. The apices of the twigs 

 are beset with polyps, of which the oral region is not completely retractile, so that the 

 collar, along with the infolded tentacles, lies over the orifice of the bilateral calyx. 



The main stem is for the most part torn away from its basis, only a part of which 

 is to be seen as a membranous expansion over the surface of a sponge. Near the base 

 the stem measures 1 1 mm. in diameter ; rising in a somewhat curved course, it becomes 

 gradually thinner. The points of the stem and of the twigs have been broken off, so 

 that it is difficult to reconstruct the entire form from the many broken fragments that 

 are to hand. The stem has a diameter of 7 mm. at a height of 20 cm., where it has 

 been broken. The thicker branches, 5 to 6 mm. in diameter at the base, arise, with one 

 exception, from the convex side of the stem, the lowest twig alone springing from the 

 opposite side at a level of 70 mm. The chief branches form, with the stem, angles of 

 30° to 45°. From these branches secondary branches may be produced, upon the ends 

 of which there arise at first, slender, erect, and flexible twigs, thickly beset with polyps. 

 These twigs may attain a length of 20 to 30 mm., with a thickness of 2 to 3 mm. 

 They frequently bear secondary twigs in addition to the polyps. The slender ends of 

 the branches, and also, possibly, of the stem, have the character of the terminal twigs, 

 and are studded with polyps. 



Whilst the naked main axis and the branches appear smooth on the surface, and 

 uniformly rounded, their form changes from the point at which the polyp-bearing 

 twigs arise. They become more or less flattened, chiefly where the twigs are given off, 

 and show deep furrows, giving the stem a grooved character. At the extremity of the 

 twig is a cluster of four polyps ; over the remaining portion the polyps are distributed 

 in spirals, the intervals between the individuals composing such being greater towards 



