AGES OF NATURE. 



231 



Fig. 162 



(Fig. 16'2J an extinct type oi^ animals, protected by a sheath, 

 and terminating in a conical body, somewhat similar to the 

 bone of the iSe/Jia, which a 

 commonly is the only 

 part preserved, (i.) 



487. The variety is 

 not less remarkable 

 among the Radiates. 

 There are to be found representatives of all the classes , 

 even traces of Jelly-fishes have been made out in the 

 slate of Solenhofen, in Bavaria. The Polyps were very- 

 abundant at that epoch, especially in the upper stages, one 

 of which has received the name of Coral-rag. Indeed, 

 there are found whole reefs of corals in their natural po- 

 sition, similar to those which are seen in the islands of the 

 a c e f 



Pacific. Among the most remarkable types of stony Polyps 

 may be named the fan-like Lobophyllia, {L.jlaheUum^ a,) 

 and various forms of tree-corals, Lithodendron pseudosty- 

 lina^ b.) But the gi'eatest variety exists among the Echino- 

 derms. The Crinoids are not quite so numerous as in 

 former ages. Among the most abundant are the Pentacri- 

 nus, (c.) There are also Comatula-like animals, that is to 

 say, free Crinoids (P'terocoma pinnata^ d.) Many Star- 

 fishes are likewise observed in the various stages of this 

 formation. Finally, there is an extraordinary variety of 



