ni 



thus described: — "Cutting west of Station, 310 to 530 feet 

 above tlie sea; thickness 120 feet, consisting of 65 feet of 

 tough Clay, overlain by 45 feet of Gravel and Pebble beds, 

 intermixed with Clay and Boulders." 



At Middletown the ascent of the Breiddens was commenced. 

 These hills consist of interbedded Felspathic Trap in beds of 

 the *' Lower Llandeilo " period, precisely as at Cader Idris. 

 Immediately at the base of the hiU called Moel-y-Golfa, the 

 Felspathic rock exhibits a most remarkable conglomeratic 

 character most difficult to account for, the Felspathic masses 

 being charged with rounded pebbles identical in character and 

 composition with the matrix. No foreign matter of any kind 

 is intermixed. The pebbles have evidently been rolled and 

 re-deposited in a soft bed of the same constituent materials 

 without the intermixture of any extraneous substance. That 

 these are due to mechanical force is certain, but how acting, 

 it is most difficult to explain. 



At the Meeting of the British Association at Exeter in 

 August last, a paper was read by Mr. Maw on the Trappean 

 Conglomerates of Midletown Hill, of which the following con- 

 densed account is extracted from the Report of the Transactions 

 of the Meeting : — 



" This was a description of the contemporaneous traps of Lower Silurian 

 age in the ridge known as Middletown Hill, running parallel with the 

 Breiddens, on the borders of Shropshire and Montgomeryshire. Especial 

 reference was made to the great beds of Bouldered Trap, consisting of 

 boulders of compact felstone, imbedded in a softer matrix of Felspathic Tuff. 

 The nodules occupy about half the mass of the conglomerate, and are 

 tmaccompanied by pebbles of any other rock. They vary from the size of 

 a walnut to rounded masses of more than a himdred weight. Sir Eoderick 

 Mtjiichiso:x's description of these beds was referred to, and the author took 

 exception to the term " Concretionary Trap," employed in the " Silurian 

 System," as he considered that the rounded outline of the boulders was 

 Tinquestionably due to mechanical causes. The interbedded Traps, bounded 

 on either side by Lower Llandeilo Flags, are of a collective thickness of 

 about 780 feet, including Bouldered Felstone, alternating with a whitish- 

 green Felspathic Breccia. The line of separation between the Breccia-bed 

 and Boulder Trap is remarkably sudden, and no gradation of character 

 occurs between them. The Breccia is worked for hard felspar, used for 



