686 MESSES. S. S. BTTCKMAN AND E. WILSON [Nov. 1 896, 



that the progress of erosion was continued into Bathonian time, and 

 that the conglomerate-bed of Maes Knoll was largely formed out of 

 materials derived from what was really a post-Bajocian or Bathonian 

 denudation. 



The next section shows the Marlstone and associated beds ; and 

 by measuring with the level to the conglomerate -bed of the 

 preceding section the thickness of the Dumortieria-cl&y is approxi- 

 mately ascertained. This deposit is found to be of nearly similar 

 thickness at Maes Knoll to what it is at the western end of the hill. 



Section YII a. — Maes Knoll. 70 yards east of the Spinney 

 below the Tump. 



ft. ins. ft. ins. 

 Garantian^e. 1. Congloinerate-bed. 



Dumortierle. 2. Clay and sandstones about 60 



Dispansi. 3. Grey, argillaceous stone with widely 



scattered iron grains 6 



4. Greyish-drab, argillaceous stone with 



scattered iron grains. Belernnites ... 5 



11 



Striatuli ? 5. Purplish-brown to drab, speckled stone 



with belemnites, shell sections, am- 

 monites with a drab matrix 7 



Variabilis. 6. Upper bed of blue rock with brown iron 



grains and ferruginous lumps 5 



Lower, blue rock, scattered iron grains, 

 ferruginous lumps, and lumps of a 

 dense pink stone 2 



7 



Spinati. 7. ' Marlstone Kock/ Yery dense rock, a 



ferruginous oolite. Pseudopecte?i cequi- 

 valvis. A grey sandy rock forms the 

 lower 4 inches of this bed, while the 

 upper 4 inches is richly ironshot, with 



red and yellow tints 1 7 



Margaritati? 8. Grey, thinly laminated, but massive un- 

 fossiliferous sandstone, found appar- 

 ently at its base 1 6 



The next section is on the eastern side of the hill, and it is 

 remarkable for one thing — that the Marlstone is absent ; so that at 

 this, the extreme eastern point, was found a condition of things 

 similar to that which obtains at the western end. 



Section YII b. — Maes Knoll, on the eastern flanTc, overlooking 

 .New Bam Farm. Special excavation. 



ft. ins. ft. : 

 Dumortierle. 1. Stiff, greenish clay with harder beds of 

 argillaceous sandstone, extending up 

 the hill. 



2. Pale yellowish-green sandstone, fragments 



of Dumortieria aff. prisca, D. aff. 

 radians, Hudlcstonia aff. serridens 6 



3. Bluish and yellowish arenaceous clay ... 2 6 



