124 British Association Jor the Advancement of Science. 
Mr. De la Beche called the attention of the meeting to the 
geological map of Cornwall and Devon, which he had made for 
the Ordnance Survey ; it was universally admitted to be a most 
beautiful specimen of scientific topography.—Mr. J. E. Marshall 
exhibited a section across the Silurian rocks in Westmorland, 
from Shap Granite to Casterton Fell_—Rev. D. Williams read a 
paper on the rocks of South Devon and Cornwall, which was 
followed by a communication from Mr. Austen on the fossil re- 
mains of the limestones and slates of South Devon. 
Mr. Lyell announced the discovery, in a crag pit at Newbourn, 
in Suffolk, of the teeth of several species of mammalia. ~ The 
first of these fossils was determined by Mr. Owen, to be the pos- 
terior grinder of the lower jaw of the leopard. Mr. Wood, on 
receiving this intelligence, examined carefully a large collection 
of teeth from Newbourn, and they were found to belong chiefly 
to fishes of the genus Lamna ; but among them was one which 
Mr. Owen has pronounced to be the molar tooth of a bear, and 
others which belong toa small ruminant. These fossils are all 
more or less broken, and there is no doubt they were found in 
the large pit at Newbourn, in which the teeth of fishes are abund- 
_ ant, in red crag. But, Mr. Lyell remarked, that there are many 
"vertical fissures extending downwards to the depth of 30 feet and 
more, through the red crag at Newbourn; these fissures being 
filled with the detritus of shelly red crag. It is possible therefore, 
that the mammalian teeth may have been derived from the con- 
tents of these fissures, and may consequently belong to a qualified 
epoch, posterior to that of the red crag. Mr. L. however, inclines 
to the opinion that the teeth of the mammalia and fishes will 
prove of the same age; because, although the shells of the red 
crag are almost exclusively marine, yet Mr. Wood has discovered 
at places distant only a few miles from Newbourn, a fresh-water 
Amiator, the Planorbis marginatus, and two individuals of @ 
land shell, Auricula migosotis, imbedded in the marine cfag- 
The same river, therefore, that conveyed these shells to the se; _ 
may also have carried down the remains of land quadrupeds. 
Mr. L. then mentioned the discovery of the teeth of an opossum 
in the London clay at Kyson, near Woodbridge. ‘This fossil 
was obtained, together with the teeth of fish, from the upper part 
of a bed of sand about ten feet thick, which is covered by a mass 
_ of London clay about 17 feet thick. The clay is again covered, 
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