PLATE III. 



ria. 



1. — A Polycystinous nucleus, with one spine running through it, and 

 attached at eaeli end to a plain circle of Silex. — (In slide P>. TV. 

 Camliridge, Barbados) Lithocircus, Mesoceua (V) 



2. — A similar nucleus with four Acanthometrum-shaped spines (see 

 Mnller's Mittelmeeres, &c., PI. X.) attached to it, the hooks of 

 wliicli describe part of a circle. Actiniscus (?) in slide T. Cam- 

 bridge, Barbados. 



3. — A Hyaline wand, sjiirally twisted. 



4 — ^Rhabdolithes pipa. var. Ehrenberg. 



