160 ORGANIC REMAINS. 



pectines, and terebratula. So large a proportion of its organic contents 

 occur likewise in the inferior oolite beneath, that it is difficult at present 

 to point out what seem to be characteristic. The inferior oolite or 

 dogger, on the contrary, besides including a great number of species, 

 which likewise occur in the superior strata, and a few which are repeated 

 in the lias below, is well discriminated by several remarkable fossils. 

 GastrocliEena tortuosa, trigonia striata, gervillia lata, mytilus cuneatus, 

 cuculleea reticulata, lingula Beanii, nerita costata, natica tumidula, 

 (minuta, Min. Conch.) turbo Isevigatus, solarium calix, trochus pyra- 

 midatus, and trochus bisertus, have not, 1 believe, been found in any 

 other stratum in any part of England. 



FOSSILS OF THE LIAS FORMATION. 



t 



WOOD of dicotyledonous trees, with knots and medullary rays, the external layers 

 often converted to jet, occurs in the upper and lower shales, and more rarely in the in- 

 termediate marlstone beds. 



Remains of zoophyta are universally of most rare occurrence in the lias, and 

 especially in Yorkshire. 



KADIARIA. 



Cidaris, a smooth spine ... ... PL XIII. fig. 17- In the marlstone. 



Ophiura Milleri ... ... PI. XIII. fig. 20. Staithes, in the marlstone. 



Pentacrinus. 1. Medusae (Miller, Crinoidea) Diffused in the lias, but not 



abundantly. 

 2. Briareus (Miller) 



MOLLUSCA. 



Mya literata (Min. Conch.) ... ... PI. VII. fig. 5. In marlstone, rare. 



Sanguinolaria ... ... ... PI. XIV. fig; 1. Marlstone, Rosebury, lower 



shale* Robin Hood's Bay. 



