PLATYCRINIDvE.^DICIIOCRraUS. 47 



2. Species. Dichocrinus fusiformis. (Austin.) 

 PI. V.fg. 6, a, b, c, d. 



Definition. — Dorso-central plate bipartite, hexagonal and acutely conical ; perisomic 

 plates six, much elongated, and the superior edges of five of them excavated for the 

 attachment of the rays. All the plates are smooth. Column unascertained. 



Synonymes and References. 

 Platycrinites pentangularis ? — Mill. Crm.\>. 81, jig. 1. 



Formation and Localities. 



Mountain limestone. — Yorkshire; and Mendips. 



The rays in this species appear to be ten in number, arranged in pairs. A single 

 basal ray joint articulates into each of the excavations in the five ray bearing plates. 

 On these basal joints several wedge-shaped articulations rest. These are succeeded by 

 the bifurcated rays, which are compossd of a single series of joints to their extreme 

 points. 



