392 



GENERAL SUMMARY TO 



' Geological Chart,' in which the succession of the various stratified rocks is clearly shown. 1 

 I follow this chart chiefly in the few following details, adding an asterisk to those 

 formations in which British Brachiopoda have been found. 



Cainosoic or Tertiary. 



Recent (Holocene) ... Modern deposits. 

 Pleistocene *Drift and Glacial beds. 



r *Mamraaliferous or Norwich Crag. 

 Pliocene \ *Red Crag. 



t ^Suffolk (Coralline) Crag. 



Miocene? Bovey beds. 



r Harapstead beds. 



Oligockne ? or Upper \ „ , . , 



\ Bembndge series. 



Eocene / TT , 



v. lleadon series. 



C r *Barton and Upper Bagshot beds. 



„ ( *Bracklesham and Lower Bagshot beds. 



Eocene <> 



( *London clay and Bognor beds. 



1 Woolwich clay and Thanet sands. 



Upper Oolite 

 Portlandian 



Mesozoic or Secondary. 



Maestricht beds, absent in England. 

 *Upper Chalk, with flints. 

 ♦Lower Chalk and Chalk-marl. 

 *Upper Greensand and Chloritic marl. 

 •Gault. 

 *Lower Greensand and Upper Speeton clay. 



Weald clay. 



Hastings sand. 



Purbeck beds. 

 ♦Portland rock and sand. 

 *Kimmeridge clay. 



1 In his table Prof. Morris does not include the ' Rhcetic ' or Avicula-contorta zone in the Trias 

 proper, but leaves it as a separate deposit lying between tbe Upper Trias and the Lower Lias. Lyell, at 

 p. Ill in the ' Student's Elements of Geology,' 1871, considers the ' Rhsetic' as the uppermost portion of 

 the Trias. The Rhsetic beds, in fact, seem to constitute the passage between the Keuper or New Red Sand- 

 stone and the Lower Lias. I merely allude to this point in order to mention that in Great Britain, after 

 much research, only one species of Brachiopod has been hitherto procured from the Rhsetic, viz. the 

 Discina Babeana, d'Orb. = Z>. Townshendi, Forbes, and that no Brachiopod has been hitherto discovered 

 in the Trias proper in Great Britain. Not a trace of the Muschelkalk has been found, and it is in that 

 deposit abroad where the larger number of Triassic Brachiopoda have been collected. 



