R. Lightbody — Notes on the Geology of Ludlow. 353 



In the specimen jig. 3, one of the Corallites is well preserved, 

 and shews a structure which fully justifies the doubt of MM. 

 Edwards and Haime as to the affinities of this Coral {Brit. Fossil 

 Corals, p. 164). Fig. 4 is a magnified section of one of the calices, 

 and fig. 4:a. is a more highly magnified view of part of the same. It 

 appears to be a tabulated coral, and, so far as I know, not yet fully 

 described. I am indebted to Mr. Henry Woodward for calling 

 my attention to the structure of the coral, as I should probably 

 have overlooked its peculiarity, not being myself so familiar with 

 this family as with the Crinoidea. 



YI. — Notes on the Geology of Ludlow. 

 By Egbert Lightbody, F.G.S. 



I HAVE long thought that the vallies of the Onny and the Teme, both 

 above and below Ludlow, had once formed an estuary, and that 

 the promontory on which the town stands had been thrown up by 

 some convulsion blocking up the valley, and turning the part above 

 the town into a lake, which (by faults or otherwise) eventually 

 caused an opening for the Teme between the Castle and Whitcliffe. 



Lately, in making a drain on the N.E. side of Castle-street, a 

 quantity of rather coarse, and very well rounded gravel was ex- 

 posed in situ, and below it was a bed of fine brown argillaceous sand. 

 The pebbles were Silurian, chiefly Lower Ludlow. One which 

 looks like Wenlock, contained Stromatopora concentrica ; another 

 mass was composed entirely of Bhynchonella navicula, from the band 

 at the top of the Aymestry Limestone. 



This appears to confirm most appositely my original opinion, as 

 the gravel is very similar to that found in the bed of the valley, 

 both above and below the town, and appears to have been elevated 

 with the site of the town. It could hardly have been deposited since 

 the elevation. The line of fault, which appears to have accompanied 

 the upthrow, runs east and west (about 100 yards north of this 

 gravel), and I believe is crossed by another fault, running between 

 the Castle and Whitcliffe, and giving passage to the Teme. 



About half a mile east, at the Gravel Hill, and at 40 feet higher, 

 there is a fine bed of gravel, but of a very different kind, consisting 

 principally of the debris of the Old Eed, chiefly Cornstone, and 

 which makes binding and solid-surfaced gravel walks, in consequence 

 of the clay mixed with it, whereas the lower level gravel, as well as 

 the small outlier, which I first mentioned, is perfectly loose, and 

 consists principally of Silurian and Cambrian pebbles, washed down 

 from the upper Onny valley and mixed with sand, which sometimes 

 occurs in thin beds. 



In the first instance, when was this Upper Gravel deposited ? It 

 must have been formed at the time of the denudation of the thick 

 series of Old Eed Beds, that once filled up the interval between the 

 Titterstone, and Brown Clee Hills ; the Clee Hills themselves being 

 preserved b}-^ the capping of Basalt spread over them. 



VOL. VI.— NO. LXII. 23 



