part 4] jUKASsic cheots^ologt. 447 



There is only one place ^vhei'e it is at all possible to veacli the 

 Junction-Bed in situ Avith any degree of safety — -a kind of shallow 

 gully or slide, descending from the top of the cliff along the line of 

 fault to the top of the extensive overgrown talus between the inner 

 cliff and the foreshore. I measured a section in the Junction-Bed 

 immediately above a gi'oup of three verj^ big fallen blocks on the 

 talus. The total thickness was 4 feet 7 inches ; but the only part 

 that could be reached was a joint-face, covered with stalactitic 

 matter which prevented me f]"om recording any detailed measure- 

 ments. Another section, measured in situ a few yards farther 

 east, will be described later on. The accompanying section (YIII) 

 was taken from one of a group of three immense fallen blocks. 

 Other blocks show a very similar development of the Junction- 

 Bed, but with minor variations. 



The whitish earth}^ limestone (C) forms a kind of capping to 

 the lithographic stone (D) ; but a close examination shows that 

 there is no transition. The base of C fills shallow hollows in D, 

 and cuts across the planes of lamination. The thickness of C 

 is very variable. No fossils of zonal importance were seen. 



Little more can be said concerning layer D. Mr, Buckman 

 writes {in Jiff., Febraary 1921) : ' the date of D is yerj uncertain.' 

 Layers D to D, are closely associated, and form a group with very 

 similar lithic characters, but there are small non-sequences. The 

 abundance of minute gastropoda in D,, is noteworthy. 



Below layer D- the sequence is very doubtful, and difficult to 

 determine. The rock resembling ' marlstone ' (U) is a wedge- 

 shaped mass, about 3 feet long, presumably a portion of a large 

 slab or lenticular cake of stone derived from some lower horizon. 

 Mr. Buckman has determined the Uliynchonella to be Tetra- 

 rliyncliia tliorncomhiensis, which is abundant in a bed some little 

 distance down in the Yellov*^ Sands of the Western Cliffs. 

 Presumabl}", therefore, this redeposited mass was derived from the 

 T.-tliorncombiensis Bed. Other blocks show similar lumps of 

 stone, and derived specimens of T. iliorncomhiensis and Selem- 

 nites sp. are common. 



The age of layers M (?) and M^ (?) is doubtful. In lithic 

 characters the}^ remind one of the more massive portions of the 

 falciferiim layer of the Western Cliffs, and are very similar to 

 layer M^ (?) of Section IX f which jdelded some big specimens of 

 Sarpoceras falciferum). In some blocks pieces of the T.-tliorn- 

 comhiensis Bed and redeposited Rlu/nclwnellcE are enclosed in the 

 limestone layers M (?) and M^ (?). 



At Watton Cliff the clay below the Junction-Bed is absent, 

 and the presence of derived masses of the T.-tliorncomhiensis Bed 

 indicates that erosion has removed some thickness of the upper 

 portion of the Yellow Sands. 



Section IX (p. 448) was measured in situ immediately west 

 of the point where the Lias is finally cut off by the faulted 

 Bathonian rocks, and only some 30 feet east of the position from 

 which the block measured in Section YIII must have fallen. 



