Mr. C. J. A. Meyer on the Cretaceous Rocks of Beer Head. 241 



He had collected as many as 228 species from the beds, including 

 the following new species — Avellana pulchella, Natica obliqua, and 

 Nucula Be Rancei — which he described. 



The paper was accompanied by a table of species, setting forth the 

 various beds in which the particular fossils have been met with. 



2. " On the Cretaceous Rocks of Beer Head and the adjacent 

 Cliff-sections ; and on the relative Horizons therein of the War- 

 minster and Blackdown Fossiliferous deposits." By C. J. A. Meyer, 

 Esq., F.G.S. 



The author remarked that in advancing westward from the Isle 

 of Wight the Cretaceous rocks diminish steadily, although unequally, 

 in thickness, and change slightly both in mineral character and fossil 

 contents, while the base of the series rises gradually in the cliff-sec- 

 tions. The chalk-cliffs of Beer Head, the most westerly chalk pro- 

 montory in England, owe their preservation, in his opinion, partly 

 to a local synclinal arrangement of the strata. The Cretaceous rocks 

 of the district include the following, in descending order : — 



Upper Chalk (in part) ? 

 Middle Chalk. 

 Lower Chalk. 

 Chalk Marl, 

 Chloritic Marl. 

 Upper Greensand. 

 Gault. 

 (?) 



The author described in detail the minor subdivisions of these 

 series, and gave lists of the fossils found in them in situ. The base 

 of the section is occupied by beds which he identified with those of 

 Blackdown, certainly underlying the Upper Greensand, and appa- 

 rently occupying the position of the Gault or of the Gault and 

 Upper Neocomian in part. The Warminster beds, on the con- 

 trary, were said to cap the Upper Greensand, and to be in reality 

 Chloritic Marl. The author suggested that the term Upper Green- 

 sand should be applied exclusively to beds between the Gault and 

 Chloritic Marl, and that the latter should be considered a distinct 

 division. 



May 13th, 1874.— John Evans Esq., F.R.S., President, 

 in the Chair. 



The following communications were read : — 



1. " Note on some of the Generic Modifications of the Plesiosau- 

 rian Pectoral Girdle." By Harry G. Seeley, Esq., F.L.S., F.G.S. 



The author stated that Plesiosauria differ from all living reptilia, 

 except Chelonians, in wanting a sternum, and pointed out the re- 

 semblance between the plesiosaurian coracoid and the coracoid and 

 precoracoid of Chelonians, inferring that the plesiosaurian scapulas 

 had been carried forward by the potential ossification which elon- 



PhiL Mag. S. 4. Vol. 49. No. 324. March 1875. R 



