143 



LIASSIC OPHIURIDtE. 



Section of the Marlstone at RockcUff, near Staithes. (See p. 143.) 



No. 



LiTHOLOGY. 



Thick- 

 ness. 



Organic Remains. 









Feet. 









Jet Rock. 













Jjow6r part of the Upper Lias. 









Saurians, Fish, Cephalopoda. 





Marlstone Beds. 













Total thickness of the series . 





160 









subdivided into — 













Main Ironstone Bands. 











1 



Connected blocks of hard ironstone, a 



foot 



25 



Terebratula trilineata, Y. and B. = T. 





and upwards in thickness, with 



thin 







punctata, Sow. ; very abundant. 





seams of intervening shale. 











2 



Sandy shale. 





5 







3 



Iron dogger. 











4 



Sandy shale. 





10 







5 



Iron dogger. 









Ammonites Clevelandicus, Y. and B. = A. 



6 



Sandy shale. 





15 





margaritatus, Montf. 



7 



Iron dogger. 











8 



Sandy shale. 





18 







9 



Iron dogger. 











10 



Shaley sandstone. 





10 



Am. margaritatus = A. vittatus, Y. and B. 



11 



Alternations of calcareous sandstone 



and 



40 



Belemnites paxillosus, Schloth., Pholadomya 





sandy shale, generally one sandstone 







obliquata, Phil., Modiola scalprum. Sow., 





bed alternating with a similar 



bed ; 







Lima Hermanni, Voltz., Ophioderma 





the seams covered with fossils. 









Milleri, Phil., Ophioderma carinata, Wr., 

 Ammonites capricornus, Sch. -^A. macu- 

 latus, Y., Avicula incequivalvis, Sow., 

 Pecten tBquivalvis, Sow. 



12 



Shaley marlstone. 







Ammonites maculatus, Cardium proximum, 













Hunt. 



13 



Shaley sandstone, gradually partaking of 



20 



Avicula cygnipes, Phil., Cardium trunca- 





the nature of Lower Lias shale. 









tum,'Phi[.,Rh'!/nchonella tetrahedra, Sow., 

 R. acuta, Sow. 





Lower Lias Shale. 













Thickness above the level of the sea . 





150 







