138 



of demarcation. As I have in preparation a paper on the geology and physio- 

 graphy of the Ledbury district, which may at no distant period take the form of 

 a small book, I will not now further occupy your time on this subject beyond 

 briefly giving the thickness of the various beds. 



No. . . , ^'^'• 



1 — Grey sandstone of the Old Red Formation (without fossils) - - 15 



2 — Red marls and clays with a few thin bands of stone (containing a few 



foralites) ...---- 332 



3 — Top of the true Passage Beds, Ledbury grits, or Auchenaspis Beds - 2 



4 — Blue mud (without fossils) .... 1 



5 — Ledbury grits, lower bed. (This band has head and neck plates of the 



very rare fossil fish— Auchenaspis, in some profusion, Cephalaspis, 



Pterygotus, Onchus, and other species) - - : ^ 



6 — Red and purple shales and laminated rocks, with new Cephalaspis, &c., 



a portion only of it being fossiliferous - - - - 64 



7 — Blue, muddy, soft, frangible stone of the Lower Ludlow character, with 



a few Lingulas— (the President stated he had found atrilobite here) 3 



8 — Red marls, and thin band of Old Red Sandstone - - - 7 



9 — Grey sandstone embeded in blue mud - - . - 4 



10 — Red marls with strong bands of Old Red Sandstone - - - 52 



11 — Soft bluish stone - - - - - - 1 



12— Red marls and shales - - - - - - 10 



13 — Brownish-grey band of soft stone with new Cephalaspis, Auchenaspis 



with body scales (never before seen), Lingulas, Onchus, &c. - 1 



14 — Old Red Sandstone ; tabular ; very compact - - - 4 



]5—Red shales and marls - - - - - - 4 



16 — Fine-grained Old Red Sandstone, containing Cephalaspis (new species), 



head and neck plates and body scales of Auclienaspis, Lingulas, &c. 3 



17 — Blue shales, Pterygotus, &c. - - - - - 1 



18— Red shales and marls, with narrow bands of Old Red - - 80 



19 — The Lingula bed of greenish-grey muddy shales - - - 4 



20— Red marl with thin bands of Old Red - - - - 93 



21 — Grey shales, partaking of the Downton Sandstone character - - 1 



22 — Old Red shales and marls - - - - - 15 



23 — Laminated Silurian shales - - - - - 9 



24 — Old Red Sandstone shales and marls, overlain by a downthrow of bro- 



ken-up fragments of Downton Sandstone — (this is the true base of 



the Passage Beds) - - - - - - 33 



25 — Upper Silurian ; Downton Sandstone ; retroverted westward - 8 



The bone bed is entirely absent. 



26 — Upper Ludlow shales ---.-- 140 



27 — Aymestry Limestone, containing the Pentamerus bed dwarfed down to 



one inch only in thickness - . . . . 236 



28— Transition beds - ■ - - - - 12 



•29— Lower Ludlow soft muddy rock. 



