115 



slight angles. The western boundary only is indeterminable, being 

 concealed by gravel and turf bog. The formation is divisible into 

 niarlstone and lower lias. The first is clearly exposed in the hill of 

 Prees,and contains the fossils which characterize it in Gloucestershire 

 and Worcestershire, viz., Avicula incequivalvis, Gryphcea gigantea, 

 and Pecten cequivalvis, with an Ammonite, in great abundance, re- 

 sembling A. geometricus of Phillips, 



The lower lias crops out at various points along the exterior of the 

 ellipse, particularly between Moreton Mill and Burley Dam ; near 

 the last of which places it is, in parts, bituminous and slaty, like the 

 Kimmeridge coal. Near Cloverly and Adderley the Kas shale 

 has been penetrated by shafts in search of coal to the depth of 300 

 feet, and numerous fossils have been extracted, among which 

 are, Ammonites BucJdandi, A.Conybeari, A.planicosta, A. planorbis, 



A. communis?, A. .published in Zeiten's Wirtemberg fossils, 



and four species of undescribed Ammonites ; Astarte elegans, Belem- 

 nites subclavatus (Voltz, found in the lias of Boll.), Cidaris, Gryphaea 

 incurva, G. MacCuUochii, Modiola minima; Pecten and Pullastra 

 (two unpublished species, both occurring at Brora); Plagiostoma 

 pectinoides, first published from Brora ; P. giganteum, Pentacrinites 

 scalaris, Goldfuss; Rostellaria? Spirifer, Tellina, Unio, Turritella, 

 and unpublished Serpulae ? 



Among these fossils some are universally characteristic of the 

 formation, others were first observed in the lias of the distant di- 

 stricts of Brora in Scotland, and of Boll and Banz in Germany. 

 Son)e of the sinkings produced small pieces of jet or lignite like that 

 of Whitby; others nearer the escarpment went through the lias, and 

 reached brine springs in the subjacent red marl. 



Having proved that this basin of lias reposes upon the new red 

 sandstone, the author adverts to the almost unfathomable thickness of 

 strata by which it must be separated from the coal-measures. Three 

 fourths of this tract of lias are covered with thick accumulations 

 of gravel, sand and boulders, the nature and origin of which will be 

 pointed out on a subsequent occasion. With this sketch is connected 

 an account of a new baseline of the lower lias which the author 

 has laid down upon the Ordnance map between Gloucester and Wor- 

 cester. It crosses to the right bank of the Severn in the neighbour- 

 hood of Tewkesbury, by Forthampton and Bushley, the lias occu 

 pying Longden Heath as an outlier. The lowest strata of the for- 

 mation are described as graduating into inferior green marls and 

 white sandstone of the new red sandstone at Combe Hill, Bushley, 

 Longden, Ripple, and Boughton Hill ; the characteristic strata a 

 little above the line of junction being thin, flag-like beds of blue 

 limestone and shale, characterized by Modiola Hillana, Ostrese, 

 Spines of Echini, Gryphcea gigantea, SfC, S^c. This clear escarp- 

 ment of the lower lias is of value, because the same strata are not 

 well exposed in the coast sections at Whitby and Lyme. 



A paper was afterwards read entitled, " A general view of the 

 new red sandstone series, in the counties of Salop, Stafford, Wor- 



