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 
palasontological 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 palaeozoic 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 Ked." 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 Uoloptycliius, 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. 
Foremost 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. Four feet above this, a 
TrocJius (^Selicites), and Beyrichia {Klcedent) bed is met with. This 
interesting little crustacean is the B, tuhercuJata of the Memoirs of the 
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 Pterygotus, Cepliala&ins, 
Auchenaspis, Ceratiocaris, Euryptcrus, while BeyrichicB and that other 
