SPONGES OR PORIFERA 



Fig^. 



: RED SPONGE, Long 

 Island Sound. 



much decomposed, and tlien it is washed in the water to remove all 

 of the flesh}' ])arts, leaving only the tough, horny skeleton, which 

 may he hleached in weak hydrochloric acid and hyposulphite of 

 soda. 



Sponges grow best on hard bottoms where there is a consider- 

 able current to bring food, and to pro- 

 vide them with an abundance of aerated 

 water. In Florida there are five varie- 

 ties of sponges called " sheepswool," 

 "yellow," "grass," "velvet" and "glove 

 sponges." 



The Slieepswool Sponges, (Spongia 

 equina gossijpina,), are most valuable, 

 the fishery being worth about 1 250,000 

 annuall}'. Tlie fibrous skeleton is very 

 tough and fine meshed, and the inter- 

 ior of the sponge is cavernous while 

 the outer surface is covered with woolly 



looking tufts of fibres. This is the common large bath sponge. 



The Yellow Sponge, ( Spongia agari- 

 cinaj, lacks the woolly tufts characteris- 

 tic of tlie sheepswool, and its surface is apt 

 to be fairly even, with numerous pit-like 

 pores. The fishery is worth about SfilS,- 

 000 annually. 



TJie Grass Sponge, (Spongia grami- 

 neaj, has the shape of a truncated cone 

 the broad end being uppermost. Tlie up- 

 per surface contains all of the large open- 

 ings and is usually depressed, giving the 

 sponge a cup-shape. The sides are furrowed witli numerous small 

 openings between the ridges. The fishery is worth about .f 20,000 

 annually. 



In the A'^elvet Sponge, (Spongia equina nieandi'ifof)nis,), the 

 surface is apt to show winding channels bordered by flat ridges of 

 fibre. The least valuable is the Glove Sponge (Spongia olfieinalia 

 tnhulifera, Figs. 1, 2 ), in which the surface is quite even with dense 

 fibres which project outward in fine tufts. The sponge is usually 



Fig. j: RED sr(_>NGE, Long 

 Island Sound. 



