G. SPONGIA. 171 



CROWNED. 



91. Spongia coronata. Tubulous, simple, and very 

 small; crowned with a radiation of thorns. 



Coasts of France and England. 



TUBULAR. 



92. Spongia tuhularia. Sessile, semi-oval, com- 

 pressed, stiff, and pierced ^ith longitudinal tubes ; 

 external border convex. 



Seas of America. 



ciliated. 



93. Spongia ciliata. Simple, tubulous, conical, 

 tortuous, thin and ciliated at the extremity. 



Coast of Greenland. 



SECTION V. 



Alasses foliated, or divided into Jiat lobes in the shape of 



leaves. 



FOLIATED. 



94. Spongia perfoliata. Stem simple, upright, 

 hollow, and leaved; lobes round, foliaceous, re- 

 sembling the leaves of a Crassula, incrusted, and 

 placed spirally round the stem. 



Australasian seas. 



N. B. This species is the most extraordinary and 

 remarkable of any known Spongia. 



