Vol. 51.] OF THE MID-COTTESWOLDS. 437 



Charlton Common and from Chatcombe Pitch, 1 while from a locality 

 about i mile south-east of the Seven Springs it has taken all 

 the Notgrove Freestone as well, and the Witchellia-grit is absent 

 from Pegglesworth Hill, and from Ossington Hill 1^ miles east-by- 

 north of Andoversford : so the southern boundary, as it was left by 

 the Bajocian denudation, lies on, or just to the north of a line con- 

 necting these places. But Quaternary denudation has done much 

 to narrow down even that small extent ; and so the result is that 

 south of the valley of the Chelt the Witchellia-he&s are reduced to 

 a small patch, which in extent cannot exceed 1| miles long by 

 2 furlongs broad— the length being from east of Wistley Hill to just 

 beyond the eleventh milestone from Gloucester on the Oxford road. 

 Whether the Witchellia-heds are met with at Cleeve Hill I cannot 

 yet say ; and it is to be hoped that they may be preserved elsewhere 

 in the Northern Cotteswolds. (See Postscript, p. 461). 



3. Ostrea sublobata, Deshayes,* Gryphcea cymbium, J. Buck- 

 man/ Gryphcea Buckmani, Lycett/ Gryphcea sublobata, 

 auctorum. 



A Gryphcea from the intervening beds was first figured by 

 J. Buckman as Gryphcea" cymbium. Subsequently Lycett gave to 

 the shell, taking this figure as his type, the name Gryphcea Buck- 

 mani. Later still this name was dropped in favour of Gryphcea 

 sublobata (Deshayes), which has of recent years always been applied 

 to the Gryphcea of the Gryphite-grit. It is to be noticed that the 

 Gryphcece tend to alter in the later deposits of the ' intervening beds,' 

 becoming broader, more circular, and having a more pronounced ex- 

 pansion. Now the dimensions of the fossil given by Deshayes in 

 his description (no figure) are : length 80 mm., breadth 50 mm. 

 These proportions do not agree with the dimensions of Gryphcea 

 Buckmani, which is shown by the figure to be 70 mm. long and 

 65 mm. wide : it is evidently a fossil from the lower of the ' inter- 

 vening beds,' because the specimens from the lower beds generally 

 conform to such dimensions. Still less do the proportions given by 

 Deshayes agree with those of the Gryphite-grit specimens. Six 

 examples of these give the following proportions : — ■ 



12 3 4 5 6 



Length 5 81 88 80 79 64 74mm. 



Breadth 90 87 79 78 69 69 mm. 



1 The quarry from which the section of Chatcombe Pitch was taken has now 

 been worked out entirely, so that it might not be easy to obtain the details given 

 (p. 415). Notgrove Freestone is, however, to be seen by the roadside, and this 

 appears, from somewhat obscure exposures farther east in the bank, to be capped 

 directly by Upper Trigo/iia-grit — at least that bed rests on a bed of bored free- 

 stone, somewhat shelly. The Witchellia-grit is, therefore, apparently absent 

 from here. 



2 Encyclop. metb. (Hist. Nat. des Vers) vol. ii. (1830) p. 307. 



8 Murchison's ' Geology of Cheltenham,' 2nd ed. 1845, pi. vii. fig. 3. 



* 'Grypfuece of the Gryphite-grit,' Proc. Cotteswold Nat. Field-Club, vol. i. 

 pp. 235-236. 



5 To accord with Deshayes's use of the terms. In modern nomenclature the 

 breadth is the length, and vice versa. 



