232 HISTORICAL PALAEONTOLOGY. 
“stalked” Crinoids, the Jurassic rocks have yielded the re- 
mains of the higher group of the “free” Crinoids, such as 
_ Fig. 162.—Pentacrinus fasciculosus, Lias. The left-hand figure shows a few of the 
joints of the column; the middle figure shows the arms, and the summit of the column 
with its side-arms; and the right-hand figure shows the articulating surface of one of the 
column-joints. 
Saccosoma. These forms resemble the existing “ Feather- 
stars” (Comatula) in being attached when young to some 
