1859.] WRIGHT INFERIOR OOLITE. 7 



Section I. — Leckhampton Hill, near Cheltenham. 



No. 1, the Upper Trigonia-grit, is a coarse brown ragstone, con- 

 taining many fossils, — chiefly (as moulds and impressions) of Trigonia 

 costata, Sow. \ Trigonia striata, Sow.; Terebratula spinosa, Schloth. ; 

 Ammonites ParJcinsoni, Sow. ; Clypeus Plotii, Klein ; Echinobrissus 

 c/unicidaris, Lhwyd ; Holectypus depressus, Leske. — 7 feet. 



No. 2, the Gryplum-gril , an ancient oyster-bank, composed almost 

 entirely of Grypluea snlihilmln, Desh.; PJioladomya Heraulti, Ag. j 

 7' r< bratnda Meriani, Oppel, and other shells. — 8 feet. 



No. 3, the Lower Trigonia-grit, a light-coloured, thin-bedded 

 oolitic ragstone, containing a large assemblage of Conchif< ra, with 

 several species of Echinodermata and Corals. 



No. 4. Upper flaggy bastard-freestone, well seen above the oolitic 

 marl: 26 feet thick. It represents the zone of Ammonites J 'l»,n - 

 phriesiamis, but is here almost non-fossilifcrous. 



No. 5, the Oolite-marl, or Fimbria-bed, is a cream-coloured 

 mud-stone, not unlike chalk-marl. The dominant shell is Terebra- 

 tida fimbria, Sow. : it contains likewise Lucvna Wrighti. Opp.; Lima 

 cardiiformis, Sow.; L. Pontonis, Lye.; Natica Leckhamptonensis, 

 Lye. ; Natica adducta, Phil. ; Mytilns pectinatiis, Sow. ; Astarte 

 1 1, guns, Sow. ; Nerinosa sp., CJiemnitzin sp., and masses of coral, 

 chiefly Thamnastrcea Mettemis, Edw. 



This bed was deposited under different conditions to that of the 

 freestone on which it rests, as its lower portion is slightly brec- 

 ciated, and the surface of the limestone on which that breccia rests 

 had been for some time exposed to aqueous action, and worn smooth 

 thereby. The oolite-marl measures about 7 feet in thickness, and 

 passes upwards into a marly limestone, becoming oolitic in the 

 uppermost layers. This division of the bed is about ]<> feet thick. 

 The Fimbria-bed is a eonstanl feature in the Inferior Oolite of the 

 Cheltenham district. 



No. <!. the Freestone, is a compact light-coloured oolitic lime- 

 stone. The uppermost beds are the best for building-purposes ; the 

 middle beds are of an inferior quality, and stained in pari with the 

 Lde of iron; the lower beds contain large oolitic grains, and 

 are called "roestone." The freestone, in all, is aboul LlOfeel in 



thick:. 



77/. Pea-grit. (Inferior Oolite.) 



ft. in. 



A. A brown, coarse, rubbly oolite, full of Battened con- 



cretions, cemented together by a calcareous matrix. 



When the blocks Weather, the cniicivt imis. which 



resemble flattened peas, form a very uneven surf 



It contains many fossils in good preservation .... 12 



B. A hard, cream-coloured, pisolitic rock, made up of 



flattened concretionsof aboul the thickness of th 



in A 1" 



c. A coarse, brown, ferruginous rook, composed of large 

 oolitic grains: it is readilj disintegrated by the 

 frost, and is of little economic value. Ahoul .... 20 



