Mr. H. J. Carter on new Species of Hydractiniidae. 1 1 



hard, flexible, of an ochre-brown colour, tinged here and there 

 with purple. Trunk short, solid, compact, compressed verti- 

 cally, soon dividing irregularly or subdichotomously into round 

 branches, which are confined to the lower surface, ending in 

 branchlets with subclavate ends, that appear on the upper or 

 opposite side, not reuniting or anastomosing. Hydrotheca 

 consisting of a little semitubular plate, extending outwards and 

 forwards from the side of the stem on the proximal border of 

 an aperture in the latter ; scattered thickly over all the branches, 

 but most prominent on the branchlets ; frequently represented 

 by the little hole alone in the stem where the projecting portion 

 has been worn off; scanty on the lower side of the main 

 stems. Minute structure : composed of clathrate chitinous 

 fibre throughout, whose meshes are subrectangular ; hydrotheca 

 formed of the semitubular scoop-like plate mentioned, sup- 

 ported on its proximal side by an extension of the clathrate 

 structure of the stem, and 'bordering the little hole also above 

 mentioned, which extends into the centre of the stem ; surface 

 of the larger stems bluntly microspined. Size of largest spe- 

 cimen 11 inches long by 5 inches broad, and about 1 inch thick, 

 or vertically. 



Hah. Marine ; procumbent. 



Loc. Cape of Good Hope and Port Natal. 



Ohs. There are five specimens of this species in the British 

 Museum, viz. one with no. 67. 3. 22. 1, and "Cape of Good 

 Hope " written on it, and the others ticketed no. 72.8. 1. 1, and 

 " Port Natal." Friction among the sand and waves has Avorn 

 down some of them so much as to leave nothing but the fora- 

 mina in the stems; whereby the most worn might be looked upon 

 as a different species, did not the gradation from the more per- 

 fect ones point out that this is not the case, and thus that they all 

 belong to one and the same species. Some parts still retain a 

 purple colour both externally and internally, showing that, as 

 with the other species in some parts also, this has for the most 

 part been washed out, and that the brown colour has been de- 

 rived from the chitinous fibre alone. In most of the specimens 

 thread-cells are numerous in the clathrate tissue, especially 

 towards the centre of the stems, where they can not only be 

 distinguished by their subconical form from other globular and 

 nucleated cells present (which appear like ova), but, by the 

 addition of liquor potassee, may be made to extrude the thick 

 portion of the thread. Their procumbent habit has been inferred 

 from the main stem and its branches being flattened on one 

 side, while the branches and hydrothecge are chiefly on the 

 other — much in the form of a wall fruit-tree, viz. with a flat 

 back. 



