223 



micaceous Sandstone bed of any thickness, over any large area, it does not 

 appear persistent. At Aust, it is not recognised in the form of a Sandstone 

 bed, but as indurated arenaceous shales containing the same shells, and at 

 Wainlode Cliff, as the light-coloured Sandstones of the Bone bed series — 

 associated with Avicula contorta. 



We now commence the true Bone bed series, or the group of the 

 black shales, in which are two, if not three, well defined but irregularly 

 formed bands composed of Bone breccia, in a matrix of Pyritic and 

 Micaceous Sandstone, containing the bones, teeth, palates, and coprolites 

 of Fish and Sautrians.* This black shale series may be divided into 

 three sets of beds, measuring together 8 feet 8 inches, the Upper and 

 Lower Fissile Shales in the gi-oup being divided by the well-known 

 "Bone bed" No. 9,t which does not measure more than from 1 to 1^ 

 inches in thickness. They will read thus: upon the Pullastra bed 

 No. 7 rests a series of black shales, measuring about 18 inches, with a 

 thin Pyritic Bone bed, or band, less than 1 inch thick, in the upper one- 

 third; and above this line of Bone breccia occurs another series of shales, 

 6 inches, also lined with traces of indurated shale, having Fish remains 

 scattered over and through the thin lenticular masses. Together this 

 constitutes bed No. 8 in section, and which is capped by the Bone bed 

 proper, or known as such, and which for convenience and distinctiveness 

 is marked bed 9; and we must not fail or omit to recognize in this 

 singular and remarkable Bone bx*eccia, during the time it was under 

 acciimulation, some very important considerations relative to the condition 

 of the sea, and shore, or land between tide-marks and deeper water, and 

 especially so when we see (in Western England at least) its wide 

 distribution in space, and its persistency in time; for both these conditions 

 seem to have been fulfilled as regards the precise horizon of this Bone bed 

 during the deposition of these particular Argillaceous or sandy shales, with 

 which it is intercalated and so intimately associated. Its position at 

 Aust Passage, Wainlode Cliff, Coombe, Pyle Hill, Uphill, Puriton, 

 Charlton near Lyme Regis, &c., on the eastern side of the Bristol 

 Channel, and its continuity on the western side at Penarth and places 

 on the same coast, and the West of Europe, fully attests the wide area 

 over which it extended and was deposited, and with such pei-sistent and 



* Sir Philip Egerton, in the year 1841, was one of the first to propose that these 

 shales should be classed with the Keuper Marls, purely upon palseontological 

 grounds, thus anticipating by 24 years the question now occupying so much 

 attention. 



t Schwabische Kloake of Quenstedt. 



