Yol. 6^.^ OF THE BATH-DOTJLTING DISTRICT. 417 



This is one of the quarries referred to by Mr. Hudleston as ' at 

 the Mission Chapel,' Twerton Hill. The Mission Chapel, however, 

 has been moved farther south-eastward — to the cross-roads. The 

 other quarry is overgrown, and in the section just described the 

 Fullers' Earth is not seen at the top, as appears to have been the 

 case when Mr. Hudleston was here. He recorded from this locality, 

 most likely from the Doulting Stone, ' Nerincea Guisei,' and another 

 species, also an Maria, and numerous Trigonice, Ostrece, etc. From 

 the top-beds in the now overgrown quarry the same geologist 

 obtained specimens of Nerincea, corals, ' Ceromya striata, Phola- 

 clomya Heraidti, and several species of Myacites, some in a vertical 

 position.' He also remarks that this deposit rather reminds one of 

 the ' Pholadomy a-Grit ' of Lycett or the Glypeiis-Giit. 1 



The section exposed in the Lyncombe cutting has already been 

 noticed (p. 407). There, no higher Inferior-Oolite bed than the 

 Upper IVigonia-Grit is visible, but the Upper Coral-Bed has been 

 observed near Claverton Church, between Bathford and Combe 

 Monkton. 



Between the Dundas and Avoncliff Aqueducts are numerous 

 exposures furnishing details which, considered in conjunction with 

 those noted by previous authors, enable one to indicate the sequence 

 (as developed in this neighbourhood), from certain marls below a 

 bed that Charles Moore identified with the Marlstone, to the Fullers' 

 Earth. 



Opposite Dundas the succession that Moore noticed (Proc. 

 Somerset Arch. & Nat. Hist. Soc. vol. xiii, 1866-67, p. 153), 2 in 

 ascending order, was : — - 



Thickness in feet inches* 



'Blue micaceous marl, with thin nodules of ironstone 20 



Brownish marlstone, with A. maculatus, Unicardium cardioides, 



Linqula Beanii, abundant, Crustacea, and saurian teeth 1 



Blue clay 3 



Upper Lias. — A single bed with A. Walcottii, A. serpentinus, etc. 1 



Grey clay 2 



Inferior Oolite.— Sands of 20 0.' 



The Midford Sands are exposed at many places between here and 

 the foot of the cliffs by the canal-side opposite Freshford. It was 

 from the Inferior Oolite of these cliffs that Lonsdale obtained many 

 fossils, 3 and from the basement-bed that Sir William Guise recorded 

 a considerable number indicative of the Upper Trigonia-Gvit. 4 ' The 

 higher beds represent the Doulting Stone and the Anabacia-Lime- 

 stones ; but as they are somewhat difficult of access, it is best to 

 study them in the quarry by the side of the canal at the Avoncliff 

 Aqueduct — the place where Mr. E. A. Walford found Trigonia clwpli- 

 cata and Nerincea. 



1 ' Monogr. Brit. Jurassic Gasteropoda : Gasteropoda of the Inferior Oolite ' 

 pt. i, Palgeont. Soc. (1887) p. 55. 



2 See also Proc. Geol. Assoc, vol. iii (1872-73) p. 92. 



3 Trans. Geol. Soc. ser. 2, vol. iii, pt. ii (1832) pp. 272-73. 



4 Proc. Cotteswold Nat. F.-C. vol. ii (1859-60) p. 172. 



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