330 Reports and Proceedings — Geological Society of London. 



The palfeontological divisions here described are correlated with 

 their probable equivalents in the Bristol area ; but no exact comparison 

 has been found possible in the case of the lowest beds, which occur in 

 Pinskey Gill. 



In the palseontological portion of the paper several new species of 

 Corals and one new genus are described, and the affinities of several 

 Corals and Brachiopods are discussed. 



2. "The Faunal and Lithological Sequence in the Carboniferous 

 Limestone (Avonian) of Burrington Combe, Somerset." By Professor 

 Sidney Hugh Reynolds, M.A., F.G.S., and Arthur Vaughan, M.A., 

 D.Sc, F.G.S. 



Lithology. — The series is almost continuously calcareous from the 

 base of Z to D l , where the section ends ; the Iv beds are, to a large 

 extent, shales. Crinoids are the prevalent limestone - builders 

 throughout K, Z, and C : ; in G l the rock is largely of the coarsely 

 crinoidal type known as ' petit granit ' by the Belgian geologists. 



A band of coarse oolite occurs in the upper part of K l ; but, apart 

 from this, no oolite is met with until the top of C x is reached. C 3 and 

 Sj are very largely oolitic, conspicuous white oolite prevailing at the 

 top of C 3 . There is much oolite in the upper part of S„. 



An important point is the prominent part played by Foraminifera, 

 which are the principal limestone-builders in C 3 , S 1? and much of S 3 . 

 Many of the oolitic limestones are foraminiferal ; but especially 

 in C 3 there is much limestone abounding in Foraminifera, though 

 not oolitic. 



In the upper part of S 3 peculiar concretionary limestones, showing 

 imperfect ' Cothani Marble ' structure, occur ; but these are not so 

 prominent as in other parts of the South- Western Province. 



The Burrington section agrees with the other sections in the 

 South- Western Province, in showing dolomitization in the upper 

 C x beds. A strong development of chert occurs at three levels — 

 S 3 , 7, and Z l . 



Pal&ontology . — The palaeontological portion includes notes on several 

 early mutations of well-known Carboniferous gentes, and deals, in 

 detail, with the megastomatid Michelinias and the large Caninias 

 (C patida and C. cylindrical). The essential similarity of develop- 

 mental stages in vesicular structures in widely distinct groups of 

 corals is illustrated in the cases of Caninia cylindrica and Lonsdalia 

 floriformis. 



The early Syringothyroid stage in the Carboniferous ' Spiriferinas', 

 a stage not observable in the Liassic type-species, is described, and 

 the generic designation of Syringothyris laminosa is discussed. 



A section is devoted to a comparison of the deposits at Burrington 

 Combe with those at other points of the Belgian and South- Western 

 Provinces. The great variability of deposit during the Mid-Avonian 

 period is emphasized, and the rapidity of accumulation of beds of 

 crinoidal debris is compared with the slow growth of dolomitic 

 limestone at that time. 



