232 HISTORICAL PALAEONTOLOGY. 



"stalked" Crinoids, the Jurassic rocks have yielded the re- 

 mains of the higher group of the " free " Crinoids, such as 



Fie 162 Pmtacrinus fascicutosns. Lias. The left-hand figure shows a few of the 

 ioints of the column ; the middle figure shows the arms, and the summit of the column 

 Vith its side-arms; and the right-hand figure shows the articulating surface of one of the 

 column-j oints. 



Saccosoma. These forms resemble the existing "Feather- 

 stars" (Comatula) in being attached when young to some 



