DEAD SEA-LILIES. 



75 



vellons operations to become fooled with mud. No 

 one can have walked through the Peak District of 

 Derbyshire without having observed the " screw- 

 stones," or casts of encrinital stems which protrude 



FIG. 14. SILURIAN ENCEINITES 1. Marsupiocrinus ccelatus. 

 2. Base of arms, mag. 3. Proboscis, inserted in fossil shell. 

 4. Crotalocrmus rwgosus. 5. Pelvis. 6. Flat stomach surface 

 and bases of arms. 7. Portion of 4a magnified. 



from the limestone walls that form the boundaries 

 of the roads and fields all over that region. Most 

 of our readers also will be familiar with the lovely 

 black or mottled marble pieces variegated with 

 white markings of every conceivable shape, the 

 result of section through the fossil encrinites at 



