Geological Society of London. 573 



the opinion that it is rather Newer than Older Pliocene ; that is to 

 say, it is coeval with the Red Crag, but its affinities are more with 

 the Pliocene of Italy than with the Pliocene of the North-sea region ; 

 and this seems to show that during its deposition there was no com- 

 munication between the Atlantic and the North Sea, except round 

 the north of Britain, the refrigeration of the water by the nine 

 degrees of latitude, through which Britain extends northwards from 

 St. Erth, preventing the access of the Italian group of Nass<^ to that 

 sea. This view is also strengthened by the absence of any close 

 agreement between the fauna of St. Erth and that of the not far 

 distant Pliocene of Normandy, the faunal affinities of both the older 

 and newer parts of that Pliocene (the Conglomerat a Terebratules 

 and Marnes a Nassa, regaixled by geologists as of the age of the 

 Coralline and Red Crags respectively) being more with the North- 

 Sea Crag than with the St.-Erth bed. 



As regards the geography of the immediate neighbourhood during 

 its accumulation, the bed is the deposit of a strait that joined the 

 sea on the north of Cornwall (St. Ives Bay) to that on the south of 

 the county (Mounts Bay) ; and which insulated the high ground of 

 the Land's-End district from the rest of Britain. The elevation of 

 the shell-bearing part of the clay, as ascertained for the author by 

 a set of levels run by Mr. Nicholas Whitley of Truro, C.E., who 

 first brought the bed to public notice in the " Transactions of the 

 Royal Geological Society of Cornwall," is 98 feet above mean-tide 

 mark in the Hayle estuary, near to it, the surface of the ground 

 being about 15 feet higher. Angular stones of small dimensions 

 (none yet met with by the author exceeding 3 cubic inches) occur 

 occasionally in the clay along with the shells, in amount of about 

 one pound to a hundredweight of the clay, indicating apparently, the 

 drift of coast-ice over the strait during the deposit : but the author 

 has only noticed one rounded pebble in the clay he has searched 

 through. 



2. " The Cretaceous beds at Black Ven, near Lyme Regis, with 

 some supplementary remarks on the Blackdown Beds." By the 

 Rev. W. Downes, B.A., F.G.S. 



The author described a new exposure of the Cretaceous deposits 

 at Black Ven, and stated that the Cliff-section measures 300 feet in 

 height, of which the Lias occupies 200 feet, and the Cretaceous beds 

 the remaining 100 feet. Of the latter the lower 25 feet consists of 

 black loamy clay, passing up into yellowish-brown non-calcareous 

 sands 75 feet thick, capped with chert-gravel. From one point 

 in the clay the author obtained a few fossils, the most abundant 

 being Lima parallela. The overlying sands, of ordinary Greensand 

 type, furnished no fossils, although traces of their former existence 

 occurred in some abundance. The only species identifiable from the 

 casts in loose sand was Cyprina cuneata. At about 50 feet, nearly 

 in a straight line above the point in the Gault-clay where the author 

 had obtained fossils, he discovered a small patch or nest of mostly 

 fragmentary silicified fossils, with a somewhat ferruginous matrix. 

 The most abundant species were Cijpriua cuneata and Gervillia 



