412 ME. S. S. BUCKMAN ON THE BAJOCIAN [Aug. 1895, 



Principal and to Prof. Harker ; it has led to an important dis- 

 covery. 



When I wrote my paper on the Bajocian of the Sherborne 

 district, 1 and correlated by other ammonite-evidence the Gryphite- 

 grit with the ' Fossil Bed ' of Sandford Lane (a Witchellia-'heaxiag 

 deposit), it seemed to me that I had solved the mystery of the 

 occurrence of Witchellia in the Cotteswolds. Subsequent examina- 

 tion of Cold Comfort, undertaken by noticing that the matrix of 

 this ' Ammonites Iwviusculus ' did not correspond to Gryphite-grit, 

 showed me that I had not fully mastered the problem. At Cold 

 Comfort I found Witchellia-'heaxmg beds above about 9 feet of 

 Freestone. There was apparently no other clue to the position of 

 these ammonitiferous beds, and they corresponded to nothing with 

 which I was acquainted in the Cotteswolds. It then became 

 necessary to work out their stratigraphical position, and the 

 following is the result. 



A walk along the eastern escarpment of Leckhampton Hill (see 

 Section XVII. p. 410) leads to Charlton Common, which is really 

 and actually continuous with Leckhampton Hill, though in a dif- 

 ferent parish. On the top and on the escarpment of the Common 

 are numerous openings in the ' intervening beds,' affording much 

 better sections than are obtainable on Leckhampton Hill, especially 

 in the Buckmani- and Lower Trigonia-gxits, which are very acces- 

 sible. The beds are tabulated below : — 



Section XVIII. — Charlton Common. 2 (Continuous with Leck- 

 hampton Hill, overlooking Southfield Farm and Charlton 

 Kings ; not marked on the Ordnance 1-inch map.) 



Upper Trigonia- Ragstone. ft. ins. ft. ins. 



grit. 

 NotgroveFree- 1. Whitish oolitic limestone, the upper 



stone equi- bed much bored 4 



valent. 

 Oryphite-grit. 2. Ragstone - beds, with abundant 



Gryphmce 5-0 



Buckmani-gvit. 3. Yellow sandy limestones in six beds 

 with sandy partings. 'Terebratula 

 BucJcmaniana' at 6 feet, at. 6 feet 

 7 ins. (broad form), at 7 feet 8 ins. 

 above the sand-bed. Gryphcea oc- 

 casionally in these beds ; a bed of 

 them with large wings occurs 3^ to 



4 feet above the Sand-bed 7 8 



4. The Sand-bed. Bright yellow sand 



and sandy stone G 



1 Quart. Journ. Geol. Soc. vol. xlix. (1893) p. 479. 



2 This section is the result of piecing together numerous exposures on the 

 hillside and hilltop. For this work various datum-lines have been used ; for 

 instance, the Notgrove Freestone (Bored Bed), the bed of yellow sand, and the 

 subjacent marl with Terebratula Buckmani, the hard bed overlying the Lower 

 Triffonia-gvit, the Meriani-bed, and the Upper Freestone. 



