VOL. XVII. (i) INFERIOR OOLITE— SOUTH COTTESWOLDS 85 



(vi.) Upper Tngoma-Grit {ea.v\y Garantiance) . — The Upper 

 Trigonia-Grit reposes non-sequentially upon the Buckmani- 

 Grit at Rodborough Hill, and spreads southwards over the 

 whole of the South Cotteswolds, overlopping the basset edges 

 of the inferior subdivisions of the OoUte. 



Bajocian Denudation. — Between the Upper and Lower 

 Trigonia-Gnis at Rodborough Hill is a considerable strati- 

 graphical break: the Gryphite-Grit, Notgrove Freestone, 

 WitchelUa-Gni, Bourguetia-Beds and Phillipsiana-Beds, de- 

 posits present near Cheltenham, and also deposits of Blagdeni 

 and niortensis hemera as well, are absent. It is undesirable to 

 commit one's-self to saying if all these subdivisions, or which of 

 them, were probably laid down over the site of a portion of the 

 South Cotteswolds. For the present it will perhaps be best to 

 say that some were no doubt laid down over the northern por- 

 tion of the South Cotteswolds, and were removed during the 

 Bajocian denudation, which preceded the deposition of the 

 Upper Trigonia-Grit. 



(vi.) Upper- rngom'a-Grit (cont.). — In the South Cottes- 

 wolds, except at the extreme southern end, where portions 

 look as if they had been subjected to some working-up, the 

 Upper Trigonia-Gvit is of the usual aspect — a hard, grey, shelly 

 limestone full of fossils. At Nibley Knoll it is only i foot 

 4 inches thick, and at Wotton Hill is scarcely typical ; but it 

 should be noticed that throughout this portion of the Cottes- 

 wolds fragments of Trichites are common at the top. The 

 upper surface of the Upper Trigonia-Grit is generally covered 

 with oysters, and is frequently bored, even when there is a thin 

 bed present which may be referred to the horizon of the 

 Dundry Freestone. 



(v.) Dundry Freestone (late Garantiance) . — A thin lime- 

 stone bed, sometimes occurring as lenticular masses, at others 

 as a continuous stratum, is recognisable in certain sections. It 

 rests upon an oyster-covered and bored surface of the Upper 

 Trigonia-Grit, and exhibits the same phenomena itself, only the 

 borings in it are much more conspicuous. The identification of 

 this deposit with the Dundry Freestone is only of scientific 

 interest. 



(iv.) Upper Coral-Bed {Truellei). — Above the thin bed of 

 Dundry Freestone, or where it is absent, the Upper Trigonia- 



