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J. F. BLAKE AND W. H. HTJDLESTON ON 



studied. The best-known is the one at the sonth, not far from the 

 Inn called " Five miles from anywhere." Here the extremity of a 

 low plateau is cut into by a shallow quarry, in whicm the beds dip 

 N. by W., at an angle of about 4°, so as to expose on the whole 

 about 20 feet. Generally described, it is entirely a creamy white 

 but rather irregular limestone, in parts crystalline. It contains, 

 however, several layers of considerable size, composed of Thamna- 

 strcea arachnoides, Rhabdophyllia, &c. Between the more crys- 

 talline portions are some more earthy parts, containing abundance 

 of shells, some complete, but others almost rolled into oolitic gra- 

 nules. The fossils in some beds have entirely perished, leaving, how- 

 ever, external casts, with loose internal casts inside. The corals and 

 other fossils, of which a list is given below, prove this to be the true 

 Coral Rag as we have restricted the term. It is not so rubbly as 

 many of the Rags are, but compares well in some portions with that 

 which occurs in Yorkshire, at North Grimston. It has, however, 

 in some cases a peculiar creaminess about it that is hard to match 

 elsewhere. It has very occasional admixtures of clay, but as a rule 

 may be considered exceptionally pure. The irregularity of the 

 bedding is an indication of its reef- like character, to which, and not 

 entirely to denudation, its termination may be due. 



The fossils obtained by ourselves at this pit are as follows : — 



Emarginula Goldfussi {Rom.). 

 Littorina rauricata (Sow.). 

 Turbo princeps (Gold/.). 

 Cheranitzia heddingtonensis (Sow.). 

 Neritopsis Guerrei (Heb. $ Desl.) and 



operculum. 

 Oerithium muricatum (Sow.). 

 Pholadomya decerncostata (Rom.). 

 Astarte aytonensis (Mor. §■ Lye). 

 Trigonia Meriani (Ay.). 

 Lithodomus inclusus (Ph.). 

 Opis virdunensis (Buv.). 



lunulata (Buv.). 



corallina (Dam.). 



, sp. (cf. paradoxa, Buv.). 



Phillipsi (Mor.), var. 



Cypricardia glabra (Bl. §■ H.). 

 Area quadrisulcata (Sow.). 



Area pectinata (Ph.). 



contracta (Ph.) 



Isoarca texata ( Qu.). 



multistriata (Et.) 



Gervillia aviculoides (Sow.). 



Lima rigida (Sow.). 



Pecten vimineus (Sow.). 



Anomia suprajurensis (Buv.). 



Ostrea solitaria (Sow.). 



Exogyra nana (Sovj.). 



Phynckonella, small species. 



Crustacean. 



Cidaris florigemma (Ph.). 



Pentacrinus. 



Thamnastraea arachnoides (Park.). 



Isastrsea explanata (Gold/.). 



Montlivaltia dispar (Ph.). 



Rhabdophyllia Phillipsi (Edw.). 



This remarkable fauna, with its Rhynchonella, Crustaceans, and 

 various peculiar molluscan species, shows how much our lists depend 

 upon the conditions of deposit of the beds, though we should natu- 

 rally expect somewhat of an exceptional fauna in a reef so far sepa- 

 rated from all others as this appears to be. 



The second exposure of Corallian beds in this neighbourhood is 

 at the northern end of the same low plateau. On entering this 

 quarry we see at once we have to do with a very different type of 

 rock. Here the creamy and coral-bearing limestones are not to be 

 seen ; but their place is taken by coralline oolite with large grains 

 in well-marked beds, separated by soft oolitic brash, which is also 



