Vol.52.] Otf THE UPPKR PORTION OF DUKDB* HtLt. 719 



and is carried along about the middle of the Dumortieria-beds al] 

 round the hill until it meets the main road at the south, by Elton 

 Farm, when it drops to the Marlstone level. Thence it is carried at 

 this horizon until a little east of Watercress Farm, on the southern 

 flank of the East Dundry Valley. Here it begins to rise gradually, 

 and at the head of the valley, at the Butchers' Arms, it reaches the 

 top of the Dumortieria-beds, so that here it coincides with our 

 own map and differs seriously from that of the Survey. Returning, 

 on the northern Hank of this valley, it drops to the Marlstone level 

 just before East Dundry is reached, and along that horizon it is 

 continued until above Northwick Cottages. Here Sanders's Inferior 

 Oolite line makes a large outward bend, as much as 500 yards 

 outside our Marlstone limit. Then it returns to the Marlstone 

 level, at about the middle of the bend before reaching Maes Knoll, 

 and is carried at about this level round the hill until the main road 

 on the northern flank is again reached. It does not show that great 

 bend at this point which is so conspicuous on the Survey map. 



It will be seen, therefore, that Sanders's map, although of earlier 

 date, approximates more closely to our own than does that of the 

 Survey, and that for the western portion of the hill it is generally 

 only a little outside our ' Inferior Oolite ' limit. For the eastern 

 portion of the hill there are considerable differences between our 

 map and his^ which, like the Survey map, shows far too great an 

 area as ' Inferior Oolite.' 



XII. Summary. 



The following facts and conclusions have been brought forward 

 in this paper : — 



1. That at Dundry Hill the sequence of strata laid down during 

 the Bathonian-Bajocian ages is incomplete, because there is no 

 doposit to represent the time of the niortensis or Hwnphriesiani 

 hemerae ; in fact, during these hemera) denudation was in progress 

 at Dundry. 



2. That all the strata of the Aalenian and Bajocian ages have been 

 removed from the eastern end of the hill, so that strata of Bathonian 

 date (Garantiance hemera) rest non-sequentially upon deposits laid 

 down during the Dwnortierice hemera. 



3. That this removal has been effected by denudation in Bajocian 

 and even post- Bajocian time. 



4. That strata equivalent to what are called elsewhere Midford 

 Sands, Upper Lias, and Middle Lias (Marlstone) are present in the 

 hill, the two former attaining a maximum thickness of more than 

 60 feet, while the Marlstone crops out at many points along the 

 flanks of the range. 



5. That the officers of the Geological Survey have apparently 

 confounded the Marlstone Rock (an ironshot oolite of the date of the 

 spinati hemera) with the well-known Ironshot Oolite (of the date 

 of the Sauzei hemera), a bed nearly loo feet higher up. 



0. That in consequence of this mistake they have, round I lie 

 greater part of the hill, drawn the base of the Inferior Oolite as far 



