392 



ME. L. RICHARDSON ON THE RH^TIC 



[Aug. 1903, 



teeth of Ceratodus. This is remarkable, considering the proximity 

 to Aust, where so many have been found. Their non-record, 

 moreover, is not due to inadequate investigation of the bed, for 

 many hours' attention was bestowed upon this stratum alone. The 

 sandstone-layers considered as equivalent to Beds 13 & 14 of the 

 North- West Gloucestershire sections, and which alternate with 

 shaly deposits, are conspicuously ripple-marked, and often covered 



Step-fault, 30 yards north-east of Offa's Dyke. (See p. 391.) 







'■■"■;W 



■ ' ( ' V / // ■ 





& 



(displacement 3 ft.) (displacement 7 ft.) 



Vertical & Horizontal Scales:- 10 feet=.i inch. 



with obscure markings similar to those described to this Society by 

 Strickland on November 30th, 1842. 1 In the Bone-Bed proper 

 (No. 15) casts of lamellibranchs occur, resembling Schizodus and a 

 broad form of Modiola minima. Intervening between the beds 

 numbered 13 & 14, and 7, is a deposit of black shale 7 feet thick. 

 At 6 inches above the former deposit are 14 inches of black shale, 

 thinly laminated and very firm ; and this stratum, projecting from 

 the cliff, constitutes a prominent feature. The succeeding 5 feet 

 1 Proc. Geol. Soc. vol. iv, pp. 16-18. 



