XXVIII. — Notices and Extracts from the Minute-Book of the Geolo- 

 gical Society. 



1. — Additional Remarks on the Nature and Character of the Limestone and 

 Slate, principally composing the Rocks and Hills round Plymouth, By 

 the Rev. Richard Hennah, P.G.S. [Read Nov. 3rd, 1826.] 



IHE author refers to a former paper on this subject,, in which he confined 

 his field of observation to the narrow tract between the Plym and the Tamar. 

 He now extends its limits to Mount Batten and Slatten Heights in a southerly 

 direction. In this tract, which forms the east side of Plymouth Sound, as well 

 as the western side from Mount Edgcombe to Pudding Point, animal remains 

 are imbedded in the slate. On the eastern side the superior beds are occa- 

 sionally of an ochreous clay-slate containing thin veins of iron with Trochites 

 and stems of Encrinites : these are associated with some peculiar fossil 

 remains, the characters of which are indistinct. The lower beds consist of 

 compact white or light grey slate inclosing remains like those found in the 

 limestone and slate. An ironstone bed occurs here which is used for pave- 

 ments, and fragments of animal relics are discoverable in it. 



From the above facts the author infers, that the slate which is prolonged 

 beyond the Plymouth limestone, even as far southward as Whitesand Bay, 

 is not primitive : but he remarks that he has never perceived animal remains 

 in the slate north of that limestone. 



2. — Notice respecting a Whin-dyke in the Cooper Colliery, near Blythe, 

 Northumberland ; drawn up from the Information of Mr. Bryham, 

 Agent at the Cooper Coal Works, by W. C. Trevelyan, Esq., F.G.S. &c. 

 [Read May 18th, 1827.] 



The total length to which this dyke has been traced is 1377 yards. It 

 increases in breadth from south to north ; being 4|- yards wide near the 

 most southern point, where it has been cut through, and 21-i yards wide at 



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