CORALS AND CORAL-ANIMALS. 151 



uniiiimfornic, the disk is more s^'inmetrically ovate or circular, and ti:e tentacles, while similarl3' 

 sessile and spheroidal, are mounted on projecting rugae of the substance of the disk. Green is, 

 in this instance also, the dominant hue, represented by duller shades of dark and yellow-green, 

 which are disposed in alternate triangular bands, from the peripheral border towards the oral 

 centre. The oral area, or stomodaeum, projects centrally in the form of a cone, and is of a 

 brilliant magenta hue. In respect to this last indicated feature, it is herewith proposed to 

 associate it, in the absence of evidence of its previous discovery, with the provisional dis- 

 tinctive title of Discosoiiia nihra-oris. 



The last type of the Actinarian order inviting attention in this chapter, Ccnaiiflnis nobilis, 

 illustrated by Fig. 7 of Chromo plate III., is ot special interest, on account of its close alliance 

 with an indigenous British species ; also with reference to the fact that it belongs to that more 

 abnormal group in which the polyps either lie entirely unattached, and repose with their bodies 

 simply concealed in the loose sand, or build up a sheath-like domicile through the exudation of 

 mucus, and the entanglement therein of cast-out nematocysts, or extraneously derived substances. 

 The present form belongs to the sheath-building category, and has been collected by the author at 

 Warrior and Thursday Islands, in Torres Strait, and also at Port Darwin. The body of this 

 anemone much resembles that of a large worm or beche-de-mer ; it is subcylindrical, about an 

 inch thick, some seven or eight inches long, and of a deep chocolate-brown hue. The crown of 

 tentacles that surmounts the smooth cylindrical body comprises two varieties. There is an 

 outer wreath of attenuate, almost filamentous, tentacles that springs from the peripheral margin 

 of the tentacular disk, and a second series of yet more slender tentacles, that grow out of the 

 central throat cavity of the polyps, and are only visible in a direct end-on view. The colour of 

 this inner fascicle of tentacles is usually pearl-grey ; while those that form the outer series are 

 most commonly a pale lemon-yellow, varying, among different individuals, to a dark red-brown 

 or nearly black. It was observed of the specimens collected at Warrior Island that young 

 anemones, with bodies an inch or so in length, were enclosed, in some numbers, in the substance 

 of the felt-like sheath that is constructed by the parent polyps, whence, on arriving at a more 

 mature age, they emerge to establish domiciles on their own account. The distinctive name of 

 Ccrianthits nobilis has been conferred on this type by Prof. A. C. Haddon, who, besides the 

 author, has collected the species in Torres Strait. 



ORDER II.— ZOANTHARIA. 



Apart from the more familiarly known skeletonless, solitary, sea-anemones, there is a 

 considerable group in which a greater or lesser number of individual anemone-like polyps 

 remain attached to one another by a creeping rhizome or common fleshy base, after the manner 

 of certain Alcyonaria hereafter described. These social anemones which, through continued 



