ROBERTS A RAMBLE ROUND LUDLOW. 



337 



Survey map ; and it would be well if other alterations were made in 

 it. There should, perhaps, be some distinction in colouring between 

 the Upper and Lower Ludlow — beds so different in lithological and 

 pal?eontological character. The Aymestry limestone is well laid down, 

 but, excepting the interest of its position, few geologists care to work 

 it — the shales above and below yielding finer and more valuable fossils. 

 Perhaps no palssozoic district is better worked than that of Ludlow ; 

 certainly none better pays for labour, nor can exceed it in features of 

 interest. 



I found Messrs. Cocking, Marston, and Lightbody courteous as ever, 

 and ready to "post up " the wandering geologist in the additions and 

 alterations which their discoveries are, almost daily, bringing to pass. 



"Within an easy distance of the town lie the whole series of Silurian 

 and Tilestone beds. It is to the latter that attention is now more par- 

 ticularly directed ; the remarkable forms of ichthyic and crustacean 

 life which they contain are valuable, not only in themselves, but as 

 throwing a light upon their cogeners in the Old Eed." It appears 

 likely to me that this typical Old Eed " of Herefordshire will ere 

 long be included in the Tilestone series ; for in that remarkable fish-bed 

 which lies on the top of the cornstones of the Wall Hills, Ledbury, the 

 Pteraspis and the Cetiocaris of the earlier beds are found associated 

 with Holoptychius, the earliest true carboniferous fish. Palaeontologically 

 we may have to accept this as a boundary line between the groups. I 

 could not learn that this fish-bed has been met with elsewhere. 



Poremost in the Ludlow geology, stands the Upper Ludlow fish-bed ; 

 this has been often described ; its " brown-gingerbread " structure, 

 charged with the scales and broken-up spines of small predatory fishes, 

 and having a great resemblance to a mass of the broken elytra of beetles, 

 is well known to all lovers of Silurian beds. Pour feet above this, a 

 ! Trochus {Selicites), and BeyricMa {Klcedeni) bed is met with. This 

 interesting little crustacean is the B. tuberculata of the Memoirs of the 

 I Geological Survey. This is the Downton Sandstone. Higher still is a 

 well-marked fucoidal band. Then upon thirty feet or more of Downton 

 Sandstone lie the transition shales, exposed along the railway-banks, 

 and at the Paper Mill. This is a bed of high interest, and has a wide 

 and interesting range of fossil contents. 



Its fish and crustacean remains comprise Fterygotus, CepTialaspiSf 

 AuchenaspiSf Ceratiocarisj EurypteruSf while Beyrichice and that other 



