THE EUROPEAN SEAS. 



133 



islands. Rhodes is the seat of one of the depots 

 of the sponges of commerce. 



"The species which live immediately along the 

 shore, near the water's edge, though often large, 

 are worthless : these are of many colours ; some, of 

 the brightest scarlet or clear yellow, form a crust 

 over the faces of submarine rocks ; others are large 

 and tubular, resembling Holothurioe in form, and 

 of a gamboge colour, which soon turns to dirty 

 brown when taken out of the water ; others again 

 are lobed or palmate, studded with prickly points, 

 and perforated at intervals with oscnli. These grow 

 to a considerable size, but, like the former, are 

 useless, since their substance is full of siliceous 

 spicule." 



The larger kinds are not found deeper than thirty 

 fathoms, and most of them within a third of that 

 depth. A few small species live at very great 

 depths, and one, a Grantia, was taken alive in the 

 Gulf of Macri in 185 fathoms water. 



The sponge of commerce {Spongia communis) is 

 found attached to rocks at various depths, between 

 three fathoms and thirty fathoms. When alive, it 

 is of a dull bluish black above, and dirty white be- 

 neath. There are several qualities, possibly indi- 

 cating as many distinct species. The best are taken 

 from about the Cyclades. 



The common sponge of the Eastern Mediterranean 

 is said to occur in the Bed Sea and Indian Ocean. 



