423 J. Prestwich, Esq., on the 



The following is the list of the fossils procured by me in this district : 



Cahjmene Blumenbachii, — very scarce, I found but one specimen at Lincoln Hill. 



Asaphus caudatus, rare. 



Euomphalus riigosus, Sowerby's Mineral Conchology, very common at Benthall Edge. 



funatus, Sow., less common at Benthall Edge and Lincoln Hill. 



discors, Sow., less common at Benthall Edge. 



Pleurotomaria, rare. 



Cornulites serpularius, Schlotheim Petrefactenkunde, rare. 



Orthoceras nnnulatum, Sow., and 0. giganteiim ? Sow., rare. 



Atrypa (Terebralula) affinis, Sow., numerous at Benthall Edge and Lincoln Hill. 



Leptcena (Producta) depressa, Sow., and L. (Producta) euglypha, Sow., common at ditto. 



Oitliis ruslica, Sovj., common at ditto. 



Lingula, large species, very rare. 



Spirifcr radlatus. Sow., common at Benthall Edge. 



Stromatopora concentrica, Goldfuss Petrificata, common at Benthall Edge. 



Calenipora cscharoides, Lamarck Anim. sans Vertebres, ditto. 



Millcpora repens, Hisinger Lethaea Suecica, ditto. 



Favoaites Golhlandica, Lamk., and F. alueolaris, Goldfuss, ditto. 



Porites pijriformis, Ehrenberg, Berlin Trans., 1832, ditto. 



Cyalhophy/lum hexagonum, Goldf., common. 



Cyalhocr mites rugosus, Miller's Crinoidea, very abundant at Gleedon Hill. 



In this and other lists of Silurian fossils, only those species are included 

 which were found by myself, and of those only a portion, a great number not 

 being yet described. I must refer to Mr. Murchison's work on the Silurian 

 System for complete catalogues ; see also the list p. 490. 



Ludlow Rocks. (Pi. XXXV. and XXXVL, figs. 1 and 9 to 14.) 

 Mr. Murchison, after determining the geological position of this zone of 

 rocks, examined it as far as Much Wenlock, and along the New Cut at The 

 Dean near Broseley ; I have traced its prolongation from Much Wenlock to 

 near Apley, at various points, where they have been protruded from beneath 

 the coal-measures by the action, which produced the great faults that tra- 

 verse this district. 



T/ie lowest division consists of greenish gray, slightly micaceous, soft sand- 

 stone and flags, with calcareous shales and impure limestone, inclosing a few 

 casts of a Pentamerus and an Atrypa. It appears in the valley of Much Wen- 

 lock, whence it ranges to Wyke, but it disappears at Posenal, underneath the 

 coal-measures ; below which, however, it trends through Broseley to Made- 

 ley, and parallel to the strike of the Wenlock limestone. The gorge of 

 the Severn exposes a small portion of this rock at the Iron Bridge. It has 

 been met with in the meadow-pits in Madeley parish and at the Tuckiss, 

 Balls, and other pits in Broseley parish. It also crops out from below the 

 coal-measures in the lower part of Darley Brook, and it ranges thence to 



