INFERIOR OOLITE AMMONITE-ZONES. 



151 



EiG. 11. — Section of Leclchampton Hill, near Cheltenham. 



Leckhampton Hill. 



1. Trigonia-bed. 



2. Gryphaea-bed. 



3. Brown rubbly oolite. 



4. Flaggy freestone. 



5. Fimbria-bed or Oolite-marl. 



6. Freestone. 



A, B, c. Pea-grit and ferruginous oolite. 



D. Cephalopoda- or Jurense-zone. 

 E, F, G. Upper Lias sand and Upper Lias clay. 



H. Marlstone. 



I. Middle Lias clay ; zone oi Aegoceras 

 Capricornus. 



No. 3. The Lower Trigonia-bed, a light-coloured, thin-bedded oolitic ragstone, con- 

 taining a large assemblage of Lamellibranchiata, which in general have their shells 

 preserved, with several species of Ecldnodermata and Anthozoa. 



No. 4. Upper flaggy bastard-freestone, well seen above the Oolite-marl : twenty-six 

 feet thick. It represents the zone of Stephanoceras Humphriesianum ; this rock is here 

 almost non-fossiliferous, although the equivalent bed at Cleeve Hill contains a rich fauna. 



No. 5. The ¥imbria-hed or Oolite-marl, is a cream-coloured mud-stone, not unlike 

 chalk-marl ; the dominant shells are Terehratida fimbria, Sow., Tereb. carinata, Lamk. ; 

 it contains likewise Lucina Wrighti, Oppel., Lima punctata, Phil., L. Pontonis, Lye, 

 Natica Leckhamptone?isis, Lye, Natica adducta, Phil., Mytilm pectinatus. Sow., Astarte 

 elegans. Sow., Nerinaa, sp., Chemnitzia, sp., and masses of Coral, chiefly Thamnastrcea 

 Mettensis, Edw. This bed was deposited under conditions very different to that of the 

 freestone on which it rests ; its lower portion is slightly brecciated, and the surface of 

 the freestone on which that breccia was deposited had been for some time exposed to 

 aqueous action and made smooth thereby. The marl measures about seven feet in 

 thickness, and passes upwards into a marly limestone, becoming oolitic in the uppermost 

 layers. This division of the bed is about ten feet thick. The Fimbria-hed is a constant 

 feature in the Lower Oolite of the Cheltenham district, and in the northern and middle 

 Cotteswolds, but is absent in the southern parts of the range. It forms the upper 

 part of the zone of Harpoceras Murchisonce . 



No. G. The Freestone is a compact light-coloured oolitic limestone ; the uppermost 



