64 



knovvn to some of tlie English residents at Canton by the name of 

 the Glass Plant. He stated that it appeared to him to be most 

 nearlv related to Gorgon'ia, although it differed widely from that 

 genus by its axis consisting, not of a single calcareous stem, but of 

 a congeries of almost innumerable siliceous filaments, slightly twisted 

 together into the form of a rope. Each of these filaments, however, 

 is composed, likę the stem of Gorgonia, of very numerous concentric 

 lamince, which are easily separated from each other by exposure to 

 heat, such as the flame of a candle, when the fibre splits down one 

 side, leaving the inner lamince exposed. Near their upper extre- 

 mity the filaments have a vvrinkled appearance, and are furnished 

 with numerous barbs, directed backwards ; towards the base they 

 taper gradually, and become much attenuated. The crust bearing 

 the polypes surrounds the mass of siliceous filaments, and a thin 

 portion of it probably envelopes each of the component filaments of 

 the rope, as it may be termed : the bark is of a leathery substance, 

 and includes a number of small spicula : its outer surface is sandy : 

 it is furnished with large, distinct, flat-topped tubercles, from which 

 the polypes are doubtless emitted, as they are from the somevvhat 

 similar tubercles of the bark of the genus Eunicea. Towards the 

 lovver end of the stem the crust is discontinued ; and this part is im- 

 bedded in a species of Sponge, which, if essential to the coral, is, 

 hovvever, independent of it, the sponge occurring without the coral, 

 but the coral not having yet been found w'ithout the sponge. The 

 coral seems to be affixed only by the intervention of the sponge, and 

 is not flattened out at the base, likę Gorgonia, for attachment to other 

 bodies. In Pennatula, which is affixed by the insertion of its lovver 

 undilated end into yielding substances, the polypiferous crust is con- 

 tinued to the extremity of the stem, and does not cease, likę that of 

 the glass-rope Coral, at the point of immersion. 



Mr. Gray remarked that this Coral is peculiar, as being the only 

 body, the animal nature of which is undoubted, that is yet knovvn to 

 secrete silica ; the spicula and axis of all other Corals vvhich have 

 fallen under his observation being pūrely calcareous : he has not, 

 hovvever, yet had an opportunity of examining the Gorgonia Briareus, 

 the axis of vvhich is described by Ellis as consisting of numerous 

 little purple glossy needles, but in the nearly allied Alcyonium ashes- 

 tinum (the spicula of vvhich closely agree vvith this description) he has 

 ascertained that the spicula are calcareous. In the siliceous nature 

 of its spicula the Coral in question agrees v* ith some of the Sponges, 

 Tethyce, Sac. 



Mr. Gray stated that this curious production had occupied much 

 of his attention several years since, and that he had delayed the 

 publication of his vievrs respecting it, in the hope of being enabled, 

 by the acąuisition of more copious materials, to clear up some points 



