1, b. — illustrates the manner in which the rays branch off. The body is enlarged in 

 this figure for the purpose of shewing the salient angles of the dorso-central plate. 



1, c. — enlarged view of the lower tentacula surrounding the pouch containing the oigans 

 of digestion. 



1, (I. — an enlarged view of a portion of the column. 



1, e. — the articulating facet of a columnar joint. The crenulations do not appear on 

 the surface of the joints in the recent species. This may be owing to the 

 presence of the animal matter still remaining in a dried and shrivelled state, and 

 concealing the hard calcareous substance of the column. 



l,f. — enlarged view of a side arm, &c. 



Specimens of the P. Caput Meduste are, we believe, still preserved in 

 the following Institutions — The British Museum ; the Geological Society's Museum ; 

 the Museum of the College of Surgeons ; the Hunterean Museum, at Glasgow ; the 

 Museum attached to the Bristol Institution ; and one or two specimens in the Museums 

 at Paris. 



