ENCRINITES. 123 



functions seem to be usurped by modern members of 

 the sea-urchin family. Stems, and sometimes small 

 heads, and the joints of the arms of an Encrinite 



Fig. 105. Stem of Encrinite most abundant in Carboniferous limestone (Poterio- 

 crinns crassus). 



nearly allied to the living Rhizocrimis y and almost 

 as small as it, are frequently found in the Chalk, 

 and especially on the surfaces of the flint nodules 



