Geological Society, 631 



Brachi/pliiilhim mammillarc ( Urongniurt). 

 Elatocladiis plana (FeistiiKintt'l). 



The Ceylon plant-bearing beds coincide, both in the composition 

 of the iK)i-a and in their relation to the older igneous rocks, with 

 those of Madras. 



2. ' Tlie Carlx)niferous Limestone (Avonian) of Broadfield 

 Down (Somerset).' By Frederick Stretton VVallis, M.Sc., F.G.S. 



This area affords yet another proof of the application of 

 Arthur Yaughan's system of zonal classification of the Avonian to 

 districts other tlian the type section of the Avon Gorge, Clifton. 



Both lithologically and )>al:eontologically the area holds an 

 intermediate position, and forms a link, between the developments 

 of the Bristol and the Mendip districts. 



A well-marked faunal assemblage (' Fossiliferous Level '), of no 

 great vertical extent, is described from the top of S^, and is shown 

 to constitute in this area a very useful field determination of 

 the datum-line between the S, and S.^ subzones. 



Piistitla tlcyans (M'Coy) is here for the first time recorded 

 from the S^ subzone. Subzones Z, and D^, hitherto unrecorded 

 from this area, are shown to be present. 



Fel)ruaiy 22n I, 1921^— Prof. A. C. Seward, Sc.D., F.K.S,, 

 President, in the Chair. 



The following communications were read : — 



1. 'Description of a New Plesiosaur from the Weald Clay of 

 Berwick (Sussex).' By Charles William Andrews, B.A., D.Sc, 

 F.K.S., F.G.S. 



The imperfect Plesiosaurian skeleton which forms the chief 

 subject of the ])resent paper was found in a large septarian nodnle 

 from the Weald Clay of Berwick (Sussex). The specimen was 

 collected by Mr. S. Tooth, who has presented it to the British 

 Museum. The parts jireserved are the posterior region of the 

 skull, numerous cervical and dorsal vertebrae (some still articu- 

 lated one with the other), the shoulder-girdle, and the humeri. 

 The pelvis and hind limbs are entirely wanting, as afto are the 

 distal portions of the fore-paddles. The bones lay mixed up, in 

 the greatest confusion, in an intensely hard matrix, from which 

 they have been, for the greater part, freed with consummate 

 skill. 



The skull is very imperfect : it seems to resemble most closely 

 the skull of Phsiosaiirus capensis Andrews, from the Uitenhage 

 Series of South Africa. The cervical vertebrie are also verj 

 similar to those of the Afi'ican species, having the central portior* 

 of the articular siu-faces deeply cujiped : the}- are, moreover, 

 interesting, on account of the jiresence in this region of well- 

 devcloi)ed inter-vertel>ral discs ("r of calcified cartilage) between 

 the successive centra. The shoulder-girdle is in an almost ]'ei-fect 



