EXTINCT ANIMALS 



tcrnal skeleton, consisting of carbonate of lime, 

 which was a very prominent feature in their 

 structure. It is of the same nature as the hard 

 box-like skeleton of the sea-urchins, which, with 



Fig. 215. — Photograph of a block of Limestone of tae Car- 

 boniferous period from Iowa, United States of America, 

 showing several kinds of Stone-lilies or Encrinites. They 

 are lettered as follows : A. Rhodocrinus kirhyi, W. and S]). 

 B. Rhodocrinus watersianus, W. and Sp. C. Platycrinus 

 planus, Ow. and Sh. D. Platycrinus symmetricus, W. and 

 Sp. E. Dorycrinus immaturus, W. and Sp. F. Dicho- 

 crinus inornatus, W. and Sp. (Photograph lent by Dr. 

 Bather). 



the star-fishes, form the great group called by 

 naturalists the Echinoderma. 



In the eighteenth century a specimen of a 

 living Encrinite or stalked star-fish was dis- 

 covered in the deep water off Martinique in the 

 West Indies, and was brought in a dried con- 



288 



