G. SPONGIA. 155 



with a level surface, but irregularly creviced ; fibres 

 stifi*, reticulated, and almost bare. 

 Indian ocean. 



THICK-LOBED. 



15. Spongia crassiloha. Incrusting, with several 

 upright lobes, which are thick and compressed, be- 

 tween an oval and cone in form, but obtuse, having 

 round holes upon the borders, irregularly ranged. 



TABULATED. 



16. Spongia tahula. Mass flat like a small plank ; 

 sides transversely and irregularly undulated, with 

 holes on the summits of the risings ; texture fibrous, a 

 little woolly, very porous, and slightly incrusted. 



Australasia. 



CAKE-FORMED. 



17. Spongia placenta. Form obliquely orbicular,^ 

 and marked with rayed furrows; texture firm and 

 very porous, fibrous> and reticulated ; holes very few, 

 and not large. 



Australasia ; King's Island. 



GAUZY. 



18. Spongia hyssMes, Mass simple, sessile, and 

 oblong, more or less swelled, spread upon marine 

 bodies ; texture very loose, transparent, gauzy, and 

 fibrous. 



Australasia. 



CUSHION. 



\d.Svo^G\ApuMnata. Sessile, oval, cushion-formed, 

 and scantily lobed ; colour orange, and sometimes olive. 

 Australasian seas. 



