HYALONEMA MIEABILIS (GEAY). 



By T. C. MAGGS, M.G.A., &c. 



\ T lias occurred to me that this very interesting sponge 

 (which was given to me a short time since by Mr. 

 Cape, of Exeter, who brought it from Japan,) may be 

 new to some of the members of our club, and that its exhibition, 

 with as much information concerning it as I have been able to 

 gather, may have more than a passing interest. 



This beautiful production of Nature has, like many of its 

 kind, been the subject of much discussion. It was first described 

 as of vegetable origin, under the name of " glass plant." Sub- 

 sequently Professor Ehrenberg and others regarded it as an 

 artificial production with which the Japanese sought to impose 

 upon the credulity of the "modern barbarian," but it is now 

 recognised as the type of the genus Hyalonema, a form of sponge, 

 and named, by Dr. E. Gray, Hyalonema mirabilis. 



The general notion of a sponge is derived from the substance 

 used for domestic and toilet purposes. The sponge before you, 

 of which I am about to give you a brief description, would 

 scarcely be recognised by the ordinary mind as related to the 

 sponge of commerce ; nevertheless, such is undoubtedly the fact. 

 The simple sarcodous substance which in one case weaves a soft, 

 leather-like, reticulated structure, in the other elaborates a silici- 



