THE CORALLIAN BOCKS OF ENGLAND. 331 



Section in Suffield Lime-quarry. 



ft. in. 



a. Thin-bedded shelly limestones, in which the forms are partially ob- 



literated. Cerithium muricatum (rare), Exogyra nana, Ostrea 

 gregaria, Pecten fibrosus, Trigonia, sp. (rare), Echinobrissus, sp. 

 (cf. clunieularis), E. scutatus; fauna micro morp hie 4 



b. Small-grained oolites with few fossils, forming the mass of the 



limestone 10 



c. Fossiliferous suboolitic limestones, with Ammonites eordatus, Avicula 



incequivalvis (? expansa), Gervillia aviculoides, Perna guadrata; 

 fauna megalomorphic. To floor of quarry, below which there 

 may be some 6 or 8 feet before reaching the next series 3 6 



17 6 



The oolites of the Lower Limestones, whose acquaintance we first 

 made in the '* White Quarry " of the Forge-valley section (fig. 11), 

 here maintain their usual poverty ; and this feature, together with 

 a smallness of the granule and a general gritty feel, may serve to 

 distinguish them. In the corresponding quarry at Silpho the 

 occurrence, though rare, of Rhgnchonella Thurmanni further serves 

 to connect their fauna with that of the Lower Calcareous Grit. 



No. 6. Not the least interesting feature of the Hackness outlier is 

 a well-developed Lower Coral Rag, of which there are indications, 

 as we shall see subsequently, in other extensions of the Lower Lime- 

 stones, but nowhere so well developed as here. 



Section of Sujjield " Sandstone " Quarry. 



ft. in. 



a. Soil and broken Rag 6 



b. Crystalline gritty coral-doggers in a brownish brash containing 



abundance of a small Waldheimia, with Spongia floriceps and 

 many other fossils 3 



c. Massive coralline block with shell-tablets. Cidaris Smithii (spines 



and test), Trichites, &c 1 9 



d. Flaggy shelly bed with a few corals imbedded in a brown gritty 



limestone 2 



e. Ferruginous brashy parting, with seams of ferric hydrate 1 



8 3 



These rest upon flaggy ferruginous limestones largely made up of 

 broken shelly matter. 



The fossils of the Rag, chiefly occurring in b, are numerous and 

 interesting. There are some peculiar forms of Ostrea. The list in- 

 cludes Ostrea, sp., 0. gregaria, 0. solitaria, Exogyra nana, Gryphaea 

 chama'formis ?, Pecten fibrosus, P. articulatus (dwarf), Hinnites velatus, 

 Lima rudis, Lima, sp., Trichites, Cypricardia (small), Astarte 

 rhomboidalis (small), Waldheimia Hudlestoni, Cidaris Smithii, 

 Spongia fioriceps, Serpula tricarinata. The corals present more 

 variety than might be found in an equal amount of the Upper 

 (true) Coral Rag of the district. We found Isastr&a explanata, 

 Thamnastrwa concinna, Thecosmilia annularis, and Rhabdophyllia 

 Phillipsi, with the inevitable Modiola inclusa. 



