THE OCEAN WORLD. 



that epoch, the Crino'idae, which we know by the name of stone-lilies, 

 and which characterises the Musclielkalk rocks, have been known under 

 the name of Encrinus, from ez/, stone, and tcptvov, a lily. 



During the eighteenth century the works upon the Crinoidse were 

 very numerous, though not very correct. They sometimes reported 

 these organic remains to be vegetable ; sometimes they were beings 



allied to the star- fishes; at 

 others they were the vertebral 

 column of fishes. Towards the 

 year 1761, however, Guettard, 

 one of the most learned natur- 

 alists of his time, understood 

 the real nature of these pro- 

 ductions. He had occasion to 

 examine a recent Encrinus 

 sent from Martinique under 

 the name of Sea-Palm, which 

 was in reality Pentacrinus 

 caput Medusas. The com- 

 parison of the living individual 

 with the fossil fragment de- 

 scribed by his predecessors, 

 and of which he had specimens 

 in his collections, enabled him 

 to ascertain the real origin 

 of the fossil Encrinoidse. 

 The beautiful fragment which 

 still exists in the Museum of 

 Natural History at Paris was 

 long considered unique, but 

 it is now known that ten 

 others exist in different mu- 

 seums. Since that date the 

 Crino'idse have been examined 

 and described by observers such 



Fig. 107. Ptntacrmus caput Medusae (Muller). T.,-. , . 



as Miller, Forbes, D Orbigny, 

 and Pictet, and very elaborately by Major Austin. 



" The species of fixed Crinoidae actually living are Pentacrinus caput 



