Vol. 52.] ON THE UPPER PORTION OF DUNORr KILL. 693 



Bed 5 is hard and massive — very distinct from the rubbly 

 condition to which the other rocks of this section have been reduced. 

 It was certainly deposited daring the Murchisonce hemera, and part 

 of it, perhaps, during the bradfordensis hemera ; but we have no 

 evidence on the latter head. 



Of the remaining deposits it will be noticed that the Ironshot 

 extends to this quarry, and that the equivalent of the Freestone is 

 very thin ; but of the beds generally we are unable to give any 

 precise details owing to the very tumbled condition in which the 

 strata are presented. There is enough evidence to show that the 

 series (Nos. 1-4) is an approximate repetition of what obtains in 

 the main-road quarries. 



Such are the sections which we have examined, and upon these 

 and the rocks which they illustrate we have now to make further 

 remarks under the following headings. 



IV. The Development of the Dundry Strata. 



In order to show the development of the various beds as well as 

 their geographical extension, we have arranged the quarry and 

 other sections according to the three lines of country : W. to E., 

 S.W. by S. from Dundry Church, and N.W. to S.E. ; and under 

 the names of the different sections, taken in this order, we have 

 placed the thickness of deposit which was formed during the several 

 hemerae — so far as we have been able to apportion it. 



The results stated in figures in the first of the accompanying 

 Tables (I.-IV) we have plotted to scale in a diagram (p. 695). 

 Concerning this diagram we would make the following remarks : — 



We have taken the base of the bifrons- and associated beds as a 

 base-line. 



We have found, as the result of numerous trials with the level 

 and many investigations, a thickness for the Dumortieria-be&s of 

 50 feet at the western end, 55 feet at East Dundry, and 60 feet at 

 Maes Knoll. 



We have found the Marlstone only in the eastern portion of the 

 hill, east of the main road, and no signs of it west of the main 

 road. It appears to be a bed which fluctuates considerably in 

 thickness ; but perhaps the fluctuation shown in the diagram may 

 be partly attributed to the imperfect state of our exposures. We 

 know that it fails altogether at the eastern end of the hill, and also 

 at the western end ; but it must be remembered that the place of 

 its westerly disappearance, as shown in our diagram, is only 

 conjectural. 



We find at Maes Knoll that the Bathonian rests directly upon 

 Toarcian — Dumortieria-beds, and that no deposits of Aalenian or 

 Bajocian age are present. 



Note. — The suggestion of false-bedding in the Freestone, and that only its top 

 bed continues above the Ironshot, must not be attributed to the authors. Tt is 

 an oversight in the representation by lines of the colour of the original diagram 



