BRITISH DEVONIAN BRACHIOPODA. 9 



" Thus it seems that there is a great mass of limestone interposed between two 

 series of shales, bounded on the top by the Rhynchonella cuboides beds, and below by 

 those containing Calceola sandalina. The upper of these two lines of junction is very 

 clearly marked, and may be observed in several shore and road-side sections, as at London 

 Bridge, Hope's Nose, Anstis Cove, Bishopstowe, and Mary church, all places in the 

 immediate neighbourhood. It is, however, only in the two former that the beds have 

 been identified by fossils. The shales above the limestone may also be distinguished in 

 the precipitous face of the rock called the Oarstone in Torbay. 



" In these upper shales there are at least four distinguishable horizons, namely, those 

 of Saltern and Lower Dunscombe, and the two at Hope's Nose. The limestone itself 

 is generally very massive, its bedding planes being few and slightly marked, and some- 

 times indistinguishable. In parts it is crowded with Corals and Stromatopora, and, 

 indeed, in some places, as at the Flat Rock (between Hope's Nose and the Oarstone), it 

 appears to be little more than a gigantic Sponge-growth ; while occasionally local 

 accumulations of Shells occur, as at Lummaton, the Oarstone, and the Torquay Cricket- 

 ground. 



"At the base of the limestone, Calceola sandalina {in sitit) has been found by 

 Mr. Champernowne at Daddy Hole Cove ; and below this are extensive series of red 

 or dark greenish-brown shaley and gritty beds, with occasional beds of fossils in the 

 condition of casts (Pleurodictyum, Cupressocrinus, and Lower-Devonian Brachiopoda). 



" The whole group, however, appears in this neighbourhood to be in a state of extreme 

 intricacy. This is due to several causes. There is a great curvature, and even overturning 

 of the beds, partly caused by the presence of igneous rocks, and partly by the sliding of the 

 rock-masses on each other. The nature of the sediment sometimes changes rapidly in 

 the same bed. Sometimes there seems an entire absence of stratification (due, perhaps, 

 to some of the limestones being organic growths rather than sedimentary deposits) ; 

 sometimes the red colouring matter from the Trias above has been worked down and has 

 marked the beds below ; and, lastly, characteristic fossils are of unfrequent occurrence . 

 compared with the larger exposures of rock, and when found are often difficult to extract 

 and badly preserved. Nevertheless, the evident ' pairing ofi"' of several of the fossiliferous 

 horizons with those of Belgium and Germany points to the discovery of a clear sequence 

 in these rocks that will establish their individuality with the Devonian system in 

 Brittany." 



In his ' Thesaurus Devonicus,' Dr. Bigsby gives a series of Tables of the Devonian 

 horizons recognised in different parts of Europe and America, and these materially 

 assist in the correlation of our British Devonian horizons with those in other parts of 

 the world. He refers to a valuable memoir by Dr. E. Kayser, pubhshed in the 

 ' Zeitschrift d. deutschen geol. Gessel. Jahrg., 1851,' p. 375, in which the Devonian 

 horizons of the Eifel are classed in the following manner : 



^ ' Transactions of the Devonshire Association,' 18/7. 



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