S98 Geological Society. 



Mr. Williams having found only a few fragments of Crinoidea and 

 a chambered univalve. 



The grits are associated, about the middle of the series, with 

 large insulated lenticular masses composed of beds of dark lime- 

 stones alternating with strata of black shale, containing plants and 

 flakes of anthracite ; also Goniatites and Posidonia. These len- 

 ticular masses may be traced, in the north of Devon, from Barn- 

 staple to Bampton, and in the south from Launceston to Drew- 

 steignton. To the east of Bampton and Drewsteignton the shales 

 not only thin out, and the whole mass becomes calcareous, but the 

 author says, that there is an upper suite of thick-bedded coral lime- 

 stones. These changes are stated to take place at Hockworthy, 

 Holcomb Rogus, Westleigh, Chudleigh, and Ashburton, emerging 

 at each locality except the last, from below the floriferous slates, 

 and accompanied by the Coddon Hill grits. At Ashburton, how- 

 ever, he states, that a fault brings the limestone abruptly in contact 

 •with the trilobite slates, the passage beds not being exhibited. 



The Coddon Hill limestones are succeeded by the lowest division of 

 No. 8, consisting of the series of slaty beds which forms the passage 

 into the trilobite slates (No. 7.). 



7. Trilobite Slates. — This group is characterized, in some locali- 

 ties, by an abundance of trilobites, particularly in the north of 

 Devon, and at Landlake in the south. It constitutes the low 

 southern flank of Exmoor, ranging from Baggy and Diamond Points 

 on the British Channel eastward to Shawley ; and Mr. Williams 

 conceives that it constitutes the south of Devonshire and the whole 

 of Cornwall, with the exception of the granitic and other igneous 

 masses. The limestones of Trenalt, Petherwin, Landlake, Ply- 

 mouth, Newton Bushell, Denbury, and Torbay, are placed in it by 

 the author ; but in the north of Devon he knows only two localities 

 at which limestone has been observed in this division. Organic 

 remains are abundant in the calcareous beds, and are well preserved. 

 The author estimates the thickness of the group to be 8^ miles. 



Tlie strata in the north of Devon and south of Somerset inferior 

 to No. 7, Mr. Williams proposes to describe in another paper. 



April 24.— A paper was first read " On the Climate of the newer 

 pliocene tertiary period," by James Smith, Esq., F.G.S. 



During an examination of the fossils contained in the marine 

 beds which indicate the latest changes in the relative level of sea 

 and land in the west of Scotland, Mr. Smith observed, that many of 

 the most common shells in the raised beds of the basin of the Clyde 

 are identical with species found by Mr. Lyell at Uddevalla in 

 Sweden* ; and he has been induced to conclude from the arctic 

 character of the testacea, that the climate of Scotland during the 

 accumulation of these beds was colder than it is at present. 



On showing some of the fossils, which are apparently extinct, to 



Mr. Gray, that naturalist noticed their great resemblance to arctic 



species. The shells still living, though not known on the coasts 



of Great Britain, but found in the raised deposits of the Clyde, 



* PhU. Trans., 1835, PI. 1. 



