374 THE GEOLOGIST. 



bcjlongiiig to thu jS^ew llud Sandstone formation. Tlicso ''basement- 

 beds" ijresont many features of novelty and interest, as might bo 

 expeeted from their position. They usually lie at some depth, and 

 have, in most cases, been brought to the surface either by a gradual 

 upheaval of the inferior deposit, or else they crop out in their due order 

 as they approach the lied Marl. While, therefore, the major portion 

 of the Lower Lias spreads over the Vale of Gloucester, and constitutes 

 a level tract of countr}^, the lowest part forms low undulating hills, 

 which become a prominent feature in the landscape, especially when it 

 presents bold cliffs on the banks of the Severn, as at Vfainlode, four 

 miles north of Gloucester ; at "Westbury, seven miles south-west of that 

 city ; and again at Aust-passage, near Bristol. A.t Wainlode there are 

 about thirty- five feet of Lias overlying sixty-five feet of Eed and Green 

 Harls. Kear the summit below a mass of black clay is a thin land of 

 hard limestone, full of oysters and raodiola), succeeded by ten inches of 

 yellow shale, below which occurs a layer of limestone, having a lami- 

 nated structure, but very hard when not weathered, in which, many 

 years ago, we discovered the first remains of insects in the Lias of this 

 district, and vvliich have since been obtained in greater or less abundance 

 wherever the same limestone has been quarried in its extension into 

 Somersetshire, Worcestershire, and Warwickshire. In Gloucestershire, 

 for the most part, it consists of one stratum of stone not exceeding two 

 feet in thickness ; and although in the counties of Worcester, Warwick, 

 and Leicester, there are three or four beds divided by shale, its litho- 

 logical characters are identical, and it is thus readily recognized, inde- 

 pendently of its peculiar and distinctive organisms, which differ widely 

 from those of the other limestones in this group. At Garden Cliff, 

 Westbury-on-Severn, it is full two feet thick, and is loaded with a 

 profusion of Monotis decussata, a small bivalve shell belonging to the 

 family Aviculida), and a few remnants of insects. Prom Wainlode it 

 may be traced to Ilasfield, on the opposite side of the river, Apperley, 

 Norton, Coombe Hill, Forthampton, near Tewkesbury, and thence by 

 Brockeridge, Streusham, and Dcfford. Yery few shells occur with the 

 insects, and those chiefly ostrea and modioloe, and rarely monotis, 

 but they are generally associated with a decapod crustacean, JEryon 

 Jiiirrovicnsisy which, in Warwickshire, attains a large size, and is 

 in a good state of preservation. A few fish, though still rare, have 

 been found in this limestone ; and in Warwickshire and Leiccstersliiro 



