288 Dr. J. E. Gray on the "Glass-Rope" Hyalonema. 



in the Museum of tlie Academy of Sciences of Philadelphia 

 which has a corona of twisted siliceous spicula, about 2 inches 

 long, which mainly differ from those of Hyalonema in size (Proc. 

 Acad. Nat. Sci. Philad. 1860, p. 85). It is said to have come 

 from Santa Cruz. May this not be a young Hyalonema in the 

 sponge? The two specimens of the genus Hyalonema which 

 Dr. Leidy examined appear to have been without the sponges at 

 the base; and as the genus is found on the coast of Portugal as 

 well as Japan, there is no reason one may not be found at Santa 

 Cruz. 



Before proceeding to make some observations on the extra- 

 ordinai-y theories that some zoologists, and some even of high 

 repute, have entertained respecting this genus, I wish to correct 

 an error into which I have fallen. 



Misled by the dry and imperfect state of the bark of the 

 specimen which I first described, and also perhaps by a pre- 

 conceived opinion that then existed that a bark-coral must be 

 an Alcyonaj'ia with pinnate tentacles, in the Synopsis of the 

 British Museum (1840), and in a paper, on the arrangement 

 of Corals, in the 'Annals and Magazine of Natural History^ 

 for 1859, I arranged the genus with the Barked Alcyonaria, 

 and formed an order for its reception, under the name of Spongi- 

 colce or Hyalophyta (Ann. & Mag. Nat. Hist. ser. 3. iv. p. 441). 

 Professor Brandt in his work has shown that they are Zoan- 

 tharia allied to Cor'ticaria, or Polyzoa having many simple conical 

 tentacles in two rows ; and Professor Bocage has also shown this 

 to be the case in the species found on the coast of Portugal. 

 The Japanese species have twenty, and the Portuguese forty 

 tentacles. 



Professor Schultze also figured the conical tentacles of the 

 Japanese species, and shows that they are, like other Zoantharia, 

 furnished with stinging darts (t. 5. f. 4 & 5). This latter author 

 goes so far as to describe the animal as a species of Polythoa, 

 under the name of P. fatua; but of this more hereafter. 



I admit that I ought not to have made this mistake; for a 

 closer inspection of the contracted cell of the polypes ought to 

 have shown me that probably they had more than eight tenta- 

 cles; and now my attention is called to the fact, I am asto- 

 nished how it could have escaped my observation before. 



The specimens which I first described from Japan had the 

 thinner tapering lower end of the coral inserted in a sponge of 

 the genus Halichondra, the lower end of the axis forming a 

 pencil of spicula at the base of the sponge. 



Professor Max Schultze figured three specimens similarly at- 

 tached to a sponge, the outer surface of the sponge being in a 

 much more perfect condition, showing the oscula, than in the one 



