Upper Chalk (in part) ? 

 Medial Chalk. 

 Lower Chalk. 

 Chalk Marl. 



376 Reports and Proceedings — 



in thickness, and change slightly both in mineral chai-acter and fossil 

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

 sections. The chalk cliffs of Beer Head, the most westerly chalk 

 promontory 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 : — 



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 contrary, 

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

 Marl. The author suggested that the term Upper Greensand should 

 be applied exclusively to beds between the Gault and Chloritic 

 Marl, and that the latter should be considered a distinct division. 



Discussion. — -Mr. Wiltshire remarked that the various beds were frequently 

 divided by lines of nodules, especially towards the bottom, and that these nodules 

 had definite forms in the different belts, in some being all rounded, in others 

 radiate. He thought it very desirable to ascertain the reason of this. With regard 

 to Ammonites rostratus, he stated that its aperture was beaked in the young as well 

 as in the adult state, and remarked that information as to its mode of growth, and 

 especially whether the successive beaks were absorbed, would be of much interest. 

 The Blackdown beds he correlated with the lower part of Mr. Price's subdivisions. 

 He also referred to the unexplained fact that a bed at the base of the Gault con- 

 tains both shells and casts. 



Mr. Carrutliers referred to the discovery in the Gault of Folkestone by Messrs. 

 Gardner and Price of cones belonging to two species of Sequoia, and associated 

 with these some species of Pitms, two of which were to be referred to a group of 

 that genus at present found associated with the two existing species of Sequoia on 

 the mountains of western North America. These Sequoics from the Gault are the 

 oldest known representatives of the genus ; and it is remarkable that they should 

 be thus early associated with species of the same group of Pines which is now 

 represented only in the same country where the Sequoia; also grow. Mr. Carruthers 

 believed this to be the earliest trace of the geographical distribution of plants which 

 now exist on the surface of the earth. 



Mr. Topley remarked that the lithological and stratigraphical break between the 

 Gault and the Neocomian is less marked than is generally supposed. At a place 

 near Folkestone the lithological difference is so small that it becomes difficult to 

 say where the one ends and the other begins. At Folkestone the highest beds of 

 the Neocomian are false-bedded sands ; and, contrary to what might be expected, 

 these sands are the most constant of the series, always occurring where the 

 Neocomian is represented below the Gault. As the Gault is traced westwards, we 

 come to places where it is difficult to discern any difference between it and the 

 Neocomian. He stated that Professor Way had found the exterior of the nodules 

 to contain more phosphate of lime than the interior, which seemed to indicate that 

 the phosphate came from without. 



Mr. Charlesworth doubted whether the fossil egg, if that of a Crocodile, could 

 be that of a living species. With regard to the forms of nodules, he remarked that 

 in the Crag the nodules round the fang-like bases of sharks' teeth were more or 

 less globular ; and he did not think that the form of nodules has any i-elation to 

 that of the nucleus around which they may have been aggregated. 



Mr. Hawkins Johnson considered the nodules to be due to organic structures, 



