MOORE ABXOEMAL SECO:sDAEY DEPOSITS. 495 



Derived from the Carboniferous 

 Limestone. 

 Terebratula hastata, Sow. 

 Orthis Micbelini, Kon. 

 Atrypa, sp. 

 Spirorbis. 



Turritella Howsei, Moore. 

 Valvata anomala, Moore. 



pygma'a, Moore. 



Vertigo Murchisoni, Moore. 



Ammonites, 2 sp. 



Belemnites acutus, Mill. 



Fish-remains abundant,includingteeth Serpulse 



of Acrodus, Hyhodus, Lepidotus, &c., ; Encrmites. 



representing about ten species. i Bryozoa, Tarious species, 



Ichthyosaurus, tooth of. | Corals, several species. 



: Echinodermata, 



■ Y. The Bath District. 



Having described the peculiar conditions under which the Secon- 

 dary rocks are found south of Bath, I shall proceed to shoAv, as I 

 have before stated, that their unconformabihty is generally still con- 

 tinued in this direction. 



The eastern edge of the Somersetshire coal-field no doubt passes 

 close to, if not immediately under Bath, the continuation of the 

 Carboniferous Limestone in this direction having been proved in the 

 trial for coal at Batheaston. Small exposures of the same limestone 

 occur at Grammar Rock, under Lansdowne, and at Wick and Cod- 

 rington, clearly marking its eastern outline. The city of Bath is 

 surrounded by Oolitic beds, except to the west, where they give 

 place, in the valley towards Bristol, to Liassic, Rhtetic, and Triassic 

 beds, and to the Coal-measures. A series of north and south faults, 

 which probably intersect the coal-basin, have brought up these older 

 deposits, and given them, close to Bath, an inclination to the east. 

 The surface of the Bath basin is covered with Postpliocene drift, 

 containing abundant traces of extinct mammalia. Wherever these 

 are passed through, they are found to lie on the upper blue marls 

 of the Lower Lias, which present long lines of furrows, channelled 

 out either by glacial action or the effects of Postphocene erosion. 

 The Rhaetic and Liassic beds are continued through the western 

 opening to Twerton, Weston, Saltford, Willsbridge, Kepisham, and 

 Bristol. The chief section in which the Ehaetic beds have been 

 exposed was at Saltford; but there at present only the L^pper " White 

 Lias" portion is seen. At all these places, excepting Keynsham 

 and near Bristol, the horizon of Lower Lias worked is the Am- 

 ononites-BiwIdandi series, which usually rest unconformably upon 

 the White Lias, and there are therefore absent from the greater 

 part of the Bath district the zones of the Insect and Crustacean 

 beds, the Ostrea-, and the Ammonites-planorhis beds of the sections 

 at Camel and Beer Crowcombe*. 



1. Pinch's Well. — A section of the beds below Bath, to the west, 

 was made under the following circumstances, which are recorded by 

 Mr. Armstrong, C.E. (" On the Tapping and Closing of a Hot Spring," 



* In the railway-cutting now in course of excavation at Newbridge Hill, 

 thin representatives of the Ostrea-hediS, are present immediately above the 

 Ehi^tic series, but are almost immediately overlain by others containing 

 Ammonites angulatus and A. BucJclandi. 



