Geological Survey, luivo laid clowji the wliulc ol' Vv'ljitoliirut Ludluw 

 as Upper Ludluw. Our frieud Mr. Cocking, soon after I came to 

 live at Ludlow, hinted to me his belief that, notwithstanding these 

 assertions, the iVyniestry Limestone was shoAvn there ; and though 

 I M'as then a novice, and quite incompetent to oifer an opinion on 

 the subject, I bore his observation in mind. Some time after, I 

 tad the great advantage of seeing Mr. Salter at Ludlow, and 

 called his attention to the subject. On breaking off a few fragments 

 of rock at the foot of the hill, he irnhesitatingly pronounced that, 

 from a fault existing in a line with the New Bridge, as far as the 

 green slope on the north side of the quarry opjiosite the next 

 Aveir, the beds at the bottom of tlie hill were Aymestry Limestone, 

 as evinced by the abundant presence of Strophemena tUosa. Since 

 that time, I have continually examined both these beds and corres- 

 ponding beds in other localities, and feel convinced that the line of 

 demarcation between the Aymestry Limestone and the Upper 

 Ludlow has been drawn in the wrong place — the Aymestry inclu- 

 ding within its limits the bands of LJiynchonella navicula which 

 Sir 11. LEuRCHisoN considers as the base of the Upper Ludlow. 

 Let it not be considered a matter of no moment Avhether this band 

 be called the bottom of one, or the top of the other, of two contig- 

 uous beds, remembering that the only way in which different beds 

 can be distinguished is by the fossils contained in them respectively. 

 iS'^ow the band of rock in (j^uestion, reaching from the recognized 

 Aymestry Limestone for about thirty or forty feet, perhaps, in 

 thickness, though included in the Aymestry, cannot be called 

 Limestone, although it is much more calcareous than any bed I 

 know of in the true LTpper Ludlow, — but it contains abundantly 

 Stropliomena fdosa and depressa, Atryim reticularis, and in the 

 lower part Linijula striata, Encrinurus pundatus and variolaris, 

 and Proetus Stokesii, all of which belong emphatically to the 

 Aymestry beds. JSTone of these fossils, I believe, can be found 

 above this horizon, while they run through the Aymestry Lime- 

 stone, and at least to the bottom of the Lower Ludlow. 



Another indication of their nature occurs in the existence, in 

 these beds over the limestone, of the honeycomb structure of the 



