426 



THE GEOLOGIST. 



The excursion occupied two days, which were devoted to examining the 

 Silurian strata. The low land to the west of Coalbrookdale, towards 

 Buildwas, is Wenlock Shale ; the lofty ridge, including Benthall Edge and 

 Lincoln Hill, is Wenlock Limestone, with the millstone- grit and coal- 

 measures reposing thereon. The following fossils were collected upon the 

 occasion, from the Wenlock Limestone : — Seliolites Murcliisonii, H. me- 

 gastoma, Propora tubulata, Favosites Forbesii, F. cristata, F. fibrosa, 

 Lebecheia conferta, Halysites catenularia, Syringopora bifurcata, S.fctsci- 

 cularis, Thecia Swindernana, Cyathopliyllum articulatum, Omphyma Mur- 

 cliisonii, Aveolites Grayii, Cystiphyllum sp., Calymena Blumenbachii, 

 Atliyris tumida, Fliynclwnella spluerica, E. nucula, P. borealis, Atrypa 

 marginalis, A. reticularis, Strophomena depressa, Fuomphalus rugosus, 

 F. discors, F. sculptus, F. funatus, F. carinatus ; from the Wenlock Shale ; 

 Fncrinital Stems, Calymena tuberculosa, Lingula sp., Orthis hybrida, O. 

 biloba, O. elegantula, Phynchonella sp., Leptena transversalis, Acroculia ? 

 Crustacea are rare at Coalbrookdale, when compared with the same forma- 

 tion at Dudley. 



Amongst the papers printed, are " On the Inferior Oolite," by the Pev. 

 S. H. Cooke, M.A. The Inferior Oolite, as developed among the Cottes- 

 wolds, especially near Cheltenham, consists of four chief divisions,— 1. Am- 

 monite Sands, about forty feet thick, by some considered to belong to the 

 Upper Lias, but probably a transition bed between that and the Inferior 

 Oolite. Pliynclionella cynocepliala, and man} r Ammonites are peculiar to it. 

 The best sections are to be seen at Frocester and the Haresfield Hills. 

 2. Pea-grit or Pisolite, about forty feet in thickness, confined to the im- 

 mediate neighbourhood of Cheltenham. 3. Freestone and Oolitic Marl 

 series, about one hundred and ninety feet thick at Leckhampton Hill ; the 

 freestone is much quarried for building, but generally unfossiliferous. 

 The Oolite marl-bed, about seven feet thick, contains many fossils. Near 

 Stroud it contains a thin coral reef, with Nerinsea. 4. Ragstone, about 

 thirty-eight feet in thickness ; a bard gritty rock, with many fossils. It is 

 subdivided into Gryphite-grit, Trigonia-grit, and Pholadoniya-grit. The 

 first of these exclusively affords Gryphcea JBuchmannii, which is also found 

 in the Swiss Jura and Swabia ; Chemnitzia, Pholadomya. and Gresslya 

 abound in this division. It maintains a nearly constant thickness over the 

 whole district, while all the inferior divisions, including the Upper Lias, 

 thin out and gradually disappear towards the east and south-east. Thus, 

 at Stonesfield the Eagstone is thirty feet thick, while all intermediate 

 strata between it and the Upper Lias are omitted ; the latter is six feet, 

 resting on the Marlstone twenty-five feet. The Inferior Oolite is also de- 

 veloped near Dundry, where the chief fossiliferous bed probably corre- 

 sponds in place with the Cheltenham Pisolite ; also in Dorsetshire, near 

 Bridport, where it forms the coast-section, but is much disturbed by 

 faults. Its fauna in these more southern localities differs much from the 

 Cotteswoldian, the Bristol coal-field having formed a complete barrier 

 between. It is also developed on the Yorkshire coast, near Scarborough. 



"On the Stonesfield Slate, and its associated Strata." By Mr. W. S. Hor- 

 ton. The term Stonesfield Slate is applied to a bed which forms the base of 

 the Bath Oolite in certain localities of the counties of Oxford, Gloucester, and 

 Northampton. It is typically developed at Stonesfield, near Woodstock, 

 and consists of a finely laminated calcareous sandstone, and although of 

 very inconsiderable thickness, rarely exceeding one foot, was formerly of 

 considerable local value for roofing-purposes. It is not exposed in open 

 quarries, but worked by means of shafts and galleries, the latter extending 

 to a considerable distance from the mouths of the pits. The blocks of slate 



