FOSSIL MOLLUSC A. 



283 



they are in the profusest abundance — young and old> 

 large and small, millions upon millions on every hand! 

 They can be taken out with the fingers — no hammer- 

 ing is required ; and if the collector has come pro- 



Fig. 2^2,—'Pileopsis wisarica. 



vided with a wire-gauzed tray to sift the finer material, 

 he will get all the lovely little shells, and plenty of 

 foramen ifera, etc., as well. Thirty or forty species of 

 fossils can be collected in a very short time. 



Fig. 273. — Teliina crassa {Crag 

 and recent). 



Fig. ZT4.—Pi'ctunculus glydmeris 

 (Red Crag and recent). 



Geologists recognize three of these Crags — the 

 Coralline, which is the oldest ; the Red Crag ; and the 

 Norwich Crag. The Coralline Crag is divided into 



