342 THE AVONIAN OP BURRINGTON COMBE. [Aug. io/ll. 



13. Faunae mid Lithological Sequence in the Carboniferous 

 Limestone Series (Avonian) of Burrington Combe (Somerset). 

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

 Vaughan, M.A., D.Sc, F.G.S. (Read May 10th, 1911.) 



[Plates XXVIII-XXXI.] 



Contents. 



Page 

 I. Introduction 342 



II. Description of the Important Rock-Types, arranged Zonally 



and Lithologically. (S. H. E.) 344 



III. Faunal Lists and Notes on the Zonal Faunas. (A. V.) 362 



IV. Paleontology. (A. V.) 371 



V. (a) Physiographical Comparison of the Burrington Sequence 

 with that at other points of the South- Western and 



Belgian Provinces. (A. V.) 385 



(b) Comparison of the Upper Palaeozoic Corals with the Lower 

 Palaeozoic Graptoiites, in regard to Occurrence, Distribu- 

 tion, and Evolution. (A. V.) 389 



I. Introduction. 



The magnificent section of Burrington Combe, first studied by 

 Prof. C. Lloyd Morgan, 1 was described in considerable detail in 

 1905 by Mr. (now Dr.) T. F. Sibly. 2 This author laid down, as 

 accurately as was possible at the time of his publication, the broad 

 zonal sequence of the faunas. The very large amount of research 

 that, during the last six years, has been devoted to the Carboni- 

 ferous Limestone Series, both in the British Isles and in Belgium, 

 has demonstrated the importance of more detailed lithological 

 investigations and the possibility of tracing the evolution and migra- 

 tion of the great Carboniferous gentes of Corals and Brachiopods. 



The field-work has extended over several years, and we owe 

 much to the willing assistance of many Bristol geologists, especially 

 to Mr. W. H. Wickes and Mr. H. F. Barke. 



The series of views (figs. 3-10, pp. 354-61) illustrate the whole 

 sequence, and are labelled with zonal and faunal indices ; the 

 precise points at which important rock-types occur are also marked 

 upon them by means of numerals. 



1 'Mendip Notes ' Proc. Bristol Nat. Soc. n. s. vol. vi (1889-91) p. 169. 



2 'The Carboniferous Limestone of Burrington Combe ' Proc. Bristol Nat. 

 Soc. ser. 4, vol. i (1904-1907) p. 14; see also A. Vaughan, ' Palseontological 

 Sequence in the Carboniferous Limestone of the Bristol Area ' Q. J. GK S. 

 vol. lxi (1905) pp. 248-50. 



