FOSSIL CIIAIUR. 



109 



shells of an unknown species of mollusk, and a 

 genus was formed for their reception, and termed 

 gyrogonites, or twisted stones, a name by which 

 they are still often designated. These fossil 

 bodies, from their extreme minuteness, are likely 

 to elude the observation of the inexperienced col- 

 lector, unless their structure and appearance are 

 particularly noted; but a reference to the figures 

 in lign. 5, will enable the reader easily to dis- 

 tinguish them, with the assistance of a pocket 

 lens. 



" . ;.£ MV/V-.IR-- 



I.IGN. 5.— FOSSIL SEED-VESSELS OP CHARGE. 



(Mr. Lye/1.) 



Fig. 1. — C/iara medicnginula ; a section showing the nut within the 

 pericarp. 

 2. — Chara tuberculala ; the pericarp. 

 3. — Portion of a spiral valve, magnified. 

 4 and 5. — The natural size of figs. 1 and 2. 



On breaking the compact limestone, the surface 

 often appears studded with small spherical cavities, 

 and these, with a lens of moderate power, will be 



f2 



