HARUWICKE'S SCIENCE-GOSSIP. 



205 



Even Derbyshire, with all its wealth of organic 

 remains imbedded in its mountain limestone, is 

 singularly free from popular names applied to the 

 fossils—" Screw-stones," perhaps, being the only 

 word. /'Pick-cheeses," in Norfolk, is the term 



are few so ornamental in their character as the 

 Cidarids (fig. 128). When denuded of their spines, 

 you see rows of knobs running down the truncated 

 globe, as in fig. 129. When the creature was alive, 

 these knobs fitted into depressions in the bases of 



Vi/.C.S 



Fig-. 132. Tubers of Hemlock Water Dropwort {OUnantJic rocata). 



applied to" the fruit of the common mallow, and as 

 the internal flint casts of Cidarids greatly resemble 

 these fruits, the name has been transferred to them 

 by the quarrymen. Of all the thousands of species 

 of fossils known to occur in ourEritish rocks, there 



spines, on the principle of a ball-and-socket, or 

 " universal " joint. The Cidarids are a very old race, 

 and not many days ago we knocked a fine example 

 out of the carboniferous limestone near Corwen, 

 with two of the spines attached. Ever since the 



