210 



THE GEOLOGIST. 



namely, some shales and sandstones underlying the rock which he regards as the 

 basement-bed of the " Dogger " or Inferior OoHte. 



These are — 1. (uppermost) Shales with Terehmtula trilineata, Belemnites 

 compressus, B. irregularis, and Trigonia Ramsayi. 2. Sandstone, yellow, 

 with Turritella, Trigonia, Astarte, Ammonites concavus, A. vaHahilis, &C. 

 3. Yellow Sandstone or Serpula-bed. 4. Grey Sandstone or Lingula-bed, 

 with Lingula Beanii, Orbicula, Belemnites compressus, B. irregularis, Ammonites 

 Moorei, &c. 



The author then observed that the Inferior Oolite in the South of England 

 admits of a palseontological subdivision into three zones, having the Fuller's Eaith 

 with Ostrea acuminata above, and the Cephalopoda-bed with Ammonites opalinus 

 beneath :• — 1st (uppermost), the zone of Ammonites ParJcinsoni ; 2d, zone of Am. 

 Hur/iphriesianus ; and 3d, zone of Am. Murchisonce. He then described the lowest 

 of these zones, that of Am. Murchisonce, giving as synonyms "Dogger" (part). 

 Young and Bird, and Phillips ; " the central and lower division of the Inferior 

 Oolite," Mui'chison ; " Fimbria-stage of the Inferior Oolite," Lycett ; " Brauner 

 Jura i8," Quenstedt ; "Calcaire l^edonien" (part), Marcou ; " Calcake a en- 

 troques," Cotteau ; " die Schichten des Am. Murchisonse," Oppel. The Leck- 

 hampton section was then described, as illustrating this zone, which was also 

 described in its details as seen at Crickley Hill, near Cheltenham, and at Beacon 

 Hill ; also at Frocester Hill and Wootton-under-Edge. 



The preceding sections exhibit the lithological character and stratigraphical re- 

 lations of the Pea-grit and Freestones, which, however, undergo great and very 

 important modifications when examined over even a limited area, — the Pea-grit 

 as regards its structiu'e ; and the Freestone, its thickness. In the Southern 

 Cotteswolds the Pea-grit loses its pisolitic character and in the eastern part of 

 the hill district the Freestones thin out and finally disappear ; the Inferior Oolite 

 being represented at Stow-on-the-Wold and at Burford by the zone of Ammonites 

 Parkinsoni, with its light-coloured ragstones, filled with an abundance of Clypeus 

 Plotii, Klein, and forming a " Clypeus-grit." 



The fossils of the Pea- grit and Freestone, and of the Oolite-marl or Fimbria- 

 bed, were then enumerated. The Oolite-marl was described as having been pro- 

 bably derived from the d6bris of a Coral-reef : its Nerinaean limestone was parti- 

 cularly alluded to. 



The section at the Peak near Robinhood's Bay afibrded the author the equiva- 

 lents of the zones of -4 m. Humphriesianu^ and Jm. Mmxhisonce, and was described 

 in hill. 



The zone of ^m. Eumphriesianvs was next treated of. Its synonyms are " In- 

 ferior Oohte of Dundry Hill," Conybeare and Phillips; " Grey limestone, Bath 

 or Great Oolite " (Yorkshire), Philhps ; " Eisenrogenstein (part) und Walk-Erde 

 Gnippe," Fromherz ; " Brauner Jiu'a y und 5," Quenstedt ; " Calcaire fermgi- 

 neux," Terquem ; " Blaue Kalke, KoraUenschicht, Giganteus-Thone, und Os- 

 treen-Kalke" (Quenstedt), Pfizenmeyer. The best types of this zone, so well 

 characterised by peculiar Gasteropods and Cephalopods and its feiTUginous oohtic 

 gi-ains, are seen in the section at Dundiy Hill, at Yeo\il and Sherbomiie in 

 Somerset, and at Burton-Bradstock and Chideoak in Dorset. Just as the thinning- 

 out of the Murchisonfe-zone and the absence of the Humphriesianus-zone near 

 Burford and other localities in the N.E. parts of the Northleach district brings the 

 Parkinsoni-zone nearly into juxtaposition with the clays of the Upper Lias, so the 

 thinning-out of the Murchisonoe-zone at DundiT Hill brmgs the zone of Am. 

 Humphriesianus into close relation with the " Sands of the Upper Lias," and has 

 caused it to be mistaken for the " Cephalopoda-bed " of Frocester and Leck- 

 hampton Hills. In the northern Cotteswolds the Humphriesianus-zone is but 

 feebly represented. 



The Dundry Hill section was then described in a note by Mr. R. Etheridge, 

 F.G.S., as comprising,— 1st (lowest), Lower Lias ; 2d, perhaps the "Lias Sands;" 

 3d, the Shell-bed ; 4th, Ammonite-bed (not equivalent to the " Cephalopoda-bed" 

 of the Cotteswolds) ; 5th to 9th, shelly beds, ragstone, fine-grained oolite, and 

 freestone ; some of the latter representing the Parkinsoni-zone. 



Dr. Wright then described the sectioii" in Gristhorpe Bay, from the Cornbrash 



