142 THE LIAS AMMONITES. 



beds of the Inferior Oolite. The Ragstones rest on them, and here appear for the first 

 time small Cosmoceras Parkinsoni, Pleurotomaria proteus, Pholadomya Heraulti, 

 P. ovulum, Cerowya Bajociana, Terehratula perovalis, Ter. spheroidalis, Ter. glohata, 

 Rhynchonella spinosa, Bhyn. plicatella, with Echinoderms, as Magnotia Forbesii, 

 Stomechinus intermedins, Echinobrissus clunicidaris, and Holectypus depressus, all forms 

 of Echinidse found for the first time in the Par/cinsoni-heds. 



The fine-grained oolite or building-stone, No. 6, resting upon the preceding, which 

 much resembles Portland stone, is extensively raised as a valuable building material. 



The coarse oolite or Freestone beds are the highest set of strata observable at Dundry 

 Hill. Shells are not common in these rocks, but several Corals are here located, as 

 Isastrcea explanata, Stylina solida, Thamnastrcsa Defranciana, Latomceandra Flemingii, 

 IsastrcBa tenuistriata, with Crinoids as Pentacrinus Milleri. 



The Oolitic rocks rest upon the Upper-Lias Sands, a, or zone of Lytoceras jurense, 

 which is seen at the western side of the hill. The sands are only from 2 to 3 feet in 

 thickness, and contain dwarfed specimens of Modiola plicata, PJioladomya fldicida, Lima 

 bellula, Belemnites irregidaris, Bel. compressus, and small Harp, insigne, so that this 

 arenaceous deposit, which attained 80 feet in thickness at Frocester and 125 feet at 

 Wootton-under-Edge, has almost disappeared at Dundry. 



The zone of Harpoceras bifrons is feebly developed at Dundry, only a few small, 

 dwarfed specimens of Harp, bifrons, Stephan. commune, Belemnites tripartitus, with a 

 Pholadomya, and a Modiola, have been found in these Upper Lias clays.^ 



The Middle Lias is here feebly represented, and in this respect presents a remarkable 

 contrast to the great development this division attains in the escarpments of the Cotteswold 

 Hills, and in the country around Bath. 



The Lower Lias in the Dundry district is well seen at Bedminster Down, Keynsham, 

 Whitchm-ch, Queen Charlton, Norton Malreward, Winford, and Barrow ; in ascending 

 from all these localities to the summit of the Hill we pass in succession from the Red 

 Marl at Bedminster, over the Avicula contorta, Planorbis, BucJdandi, Turneri, and 

 Obtusus-heAs, which have a collective thickness of 450 feet, 



I beg to refer the student to the section of the Buc/clandi-heds at Saltford, near Bath, 

 pp. 36 and 37, and of the Planorbis, and Jvia(la-co?itorta-heds in the same cutting, as 

 aflFording all the details of these strata yet known on the subject in this district. 



Those readers who may be interested in the Pateontology of the Dundry district will find in the 

 ' Proceedings of the Bristol Naturalists' Society,' vol. i, p. 9, new series, 1874, a most valuable memoir by 

 Mr. E. B. Tawney, F.G.S., entitled " Museum Notes — Dundry Gasteropoda." This paper contains a list 

 of sixty-four species, many of which are beautifully figured for the first time, and the whole are most 

 minutely and accurately described. It is an important addition to British Jurassic palseontology. 



1 For full details on the Dundry Hill section, I beg to refer to my friend Mr. R. Etheridge, F.R.S., 

 notes on Dundry Hill, in my Memoir ou the "Subdivisions of the Inferior Oolite," ' Quart. Jouru. Geol. 

 Soc.,' p. 21, vol. xvi, 1860. 



