2 J. BUCKMAN ON THE CEPIIALOPODA-BEDS OF 



ford Abbas, which we quote, as showing that Dr. Wright had at 

 this time identified the Dorset Cephalopoda-bed with the one in 

 Gloucestershire. 



" Between Yeovil and Sherborne " the " Cephalopoda-bed is well 

 developed and extensively exposed ; and at the Halfway House its 

 relations to the Sands below, and the Limestone of the Inferior Oolite 

 above, may be satisfactorily made out. Here it contains a great 

 many largo Ammonites, Nautili, and Belemnites, — as 



Ammonites dorsetensis, Wright. Belemnites breviformis, Voltz. 



jurensis, Zieten. compressus, Volt-. 



Nautilus inornatus, B 1 Orb. 



" Section VI. — At Bradford Abbas, near Yeovil, Dorsetshire. 



" Inferior Oolite. 



ft. in. 

 " a. Coarse, hard, brown ragstone, slightly oolitic, very irregularly 



bedded, and containing few fossils : about 2 



b and c. Absent. 



" Cephalopoda-bed. 



" d. A coarse, brown, oolitic ragstone, composed in part of hard, cal- 

 careous, sandy layers, grey and brown, and having softer marly 

 sandy seams running through the rock ; it breaks with an un- 

 certain fracture, and sometimes has a flinty hardness : the rag- 

 stones are speckled with dark brown flattened oolitic grains of 

 hydrate of iron, and contain many fossils : about 2 6 "* 



It was then clearly Dr. Wright's view (in which he was, indeed, 

 both preceded and followed by other geologists) that the Dorset 

 Cephalopoda-bed was identical with that of Gloucestershire ; and 

 indeed we have seen fossils from the Bradford bed just described 

 labelled as from Upper Lias. 



Mr. Strickland, in 1850, considered the ironshot oolite of Dundry 

 the equivalent of the Cephalopoda-bed of the Haresfield Hill. 

 He says, " A few miles to the south the Pisolite disappears and is 

 replaced near Painswick and at Haresfield Hill by strata containing 

 ferruginous oolitic grains in a brown paste. This is the precise 

 equivalent of the well-known oolite of Dundry, near Bristol, which 

 may be recognized as far off as Bridport, on the Dorset coast "f. 



Now this view was quoted by Dr. Wright in a paper published 

 in the ' Quarterly Journal ' for 1860, only to be dissented from ; 

 for he says of the above, " a comparison, however, of the species of 

 Ammonites and other shells collected in these different localities 

 shows that, besides a similarity in lithological structure, there is 

 nothing in common between the strata " X ', and he accounts for the 

 appearances by supposing that the Am,monites-Murchisono3 zone, by 

 thinning out, has brought the zone of Ammonites Humphresianus into 

 close relation with the sands of the Upper Lias J. 



* Quart. .Tourn. Geol. Soc. vol. xii. (185ft) p. 309. t Ibid. vol. vi. p. 250. 



I Ibid. vol. svi. p. 18. 



