426 
THE GEOIX)GIST. 
The excursion occupied two days, •n bich 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 : — HelioUtes Murchisonii, H. me- 
gastoma, Projjora tuhulaia, Favosites Forhesii, F. cristata, F. fibrosa, 
Lebecheia conferta, Halysites catetnclaria, Syringopora bifurcata, S.fasci- 
cularis, Thecia Swindernana, Cyatliophyllum articulatum, OmpJiyma Mur- 
chisonii, Aveolites Grayii, Cystiphyllum sp., Calymena Blumenbachii, 
Atliyris tumida, WiynchoneUa spharica, R. niicula, JR. borealis, Atrypa 
marginalis, A. reticularis, Strophomena depressa, Fuomphalus rugosns, 
E. discors, E. sculjjtus, E. funatus, E. carinatus; from the Wenlock Shale ; 
Encrinital Stems, Calymena tuberculosa, Lingula sp., Orthis Jiybrida, O. 
biloba, O. elegantula, RJiynchonella sp., Leptena transversalis, A(rroculia ? 
Crustacea are rare at Coalbrookdale, when com.pared with the same forma- 
tion at Dudley. 
Amongst the papers printed, are " On the Inferior Oolite," by the Hev. 
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. Ehynchonella cynocepJiala, and many 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 Tserin^ea, 4. Eagstone, about 
thirty-eight feet in thickness ; a hard gritty rock, with many fossils. It is 
subdivided into Gryphite-grit, Trigonia-grit, and Pholadomya-grit. The 
first of these exclusively affords Gryphcea BucJcmannii, which is also found 
in the Swiss Jura and Swabia ; Cheranitzia, 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 
