Euplectella sp.
 

from Survey of Invertebrates (Zool250), University of Alberta; image copyright © Ron Koss & A. Richard Palmer, used with permission)	This is a well known glass sponge from the Pacific Ocean.  The Japanese collect these and present the whole animal as a wedding gift to a bride and groom (What is the symbolism?).  The long spicules resemble, for all the world, fiberglass.  Soime students don' believe that this specimen is natural, they assume it is a model.  Contrast the preseved specimen with the skeleton. See Brusca p. 183 (fig. 1E), p. 189 (fig. 6A)