126 
that formation in Alum Bay, but are likewise found in the beds, 
Nos. 8. and 6, which occur below it. 
Mr. Bowerbank then described the strata in Alum Bay, taking 
Mr. Webster’s section as the base of his observations; and he 
pointed out, that in the beds of greenish gray sand and clay marked 
d in that section, and below the variegated sand and clays which 
underlie the London clay, he found the followmg shells, charac- 
teristic of that formation :—Venericardia planicosta, Cardita marga- 
ritacea, Mya intermedia, Cardium semigranulatum, Nucula similis, 
N. amygdaloides, Turritella conoidea, T. elongata, T. edita, Murex 
innexus, (Brander) Buccinum desertum, and Cancer Leuchii. In the 
variegated sands and clays no fossils were found. 
An extract from a letter, dated Newcastle, 14th February, 1839, 
and addressed to Dr. Buckland, by Mr. Atkinson, was then read. 
This letter accompanied a series of slabs of fissile or slaty mica- 
ceous sandstone, presenting the tortuous casts of vermiform bodies, 
either impressed in the stone or in relief. The more perfect casts 
are marked by a longitudinal line, and closely-set transverse fine 
strie. The bed from which the slabs were procured, belongs to the 
carboniferous formation near Haltwhistle in Northumberland. 
The following is the succession of strata presented by the quarry : 
Compact sandstone... 60. oie sce. de. ec enneeeraeces sve 
Red marly sandstone, with shells.............. 10 miles. 
Micaceous blue and white sandstone, containing 
the casts, the largest of which are found near the 18 f, 
centre of the bed. The stone splits into thin eet: 
flags, and is used for roofing................ 
Wonmpact sandstone, hen ee ie oie OM 
Limestone containing in one part a few oe Brin ae 
‘RETITE TONS) ih ene A Bhar aS Borg ie 3 chal samy arate 
The strata dip 154° to the $.S.W. 
Mr. Atkinson is of opinion that the impressions are principally 
due to worm-tracks. 
A paper was afterwards read, “On the relative ages of the ter- 
tiary deposits commonly called Crag, in Norfolk and Suffolk,” by 
Charles Lyell, Esq., V.P.G.S. 
This paper contains the results of Mr. Lyell’s examination of the 
crag, with reference to the three following points:—First, The 
direct superposition of the red to the coralline crag, as originally 
pointed out by Mr. Charlesworth in 1835 : Secondly, Whether the 
remains of mammalia are really imbedded in regular and undis- 
turbed marine strata in the Norwich crag: Thirdly, Whether the 
proportion of recent shells, as compared to the extinct, is decidedly 
larger in the crag of Norwich, so as to indicate a posteriority in age 
relatively to the Suffolk crag. 
1. Of the superposition of the red on the coralline crag, the 
author found distinct proofs in the sections at Ramsholt and Tat- 
tingstone, aS previously indicated by Mr. Charlesworth, and in 
