378 Geological Society. 



sionally alternating with contemporaneous porphyries) of great thick- 

 ness occasionally present fossil bands with Asaphus Buchii, &c. 

 These are below the level of the limestone seen in the Arrenig sec- 

 tion. 2. That the limestones near Bala (three of which are on the 

 line of section, and one at a still lower level) contain fossils which 

 point to a lower level than the Caradoc sandstone, and rather con- 

 form, especially in the lower beds, to the character of the Llandeilo 

 flagstone. 3. That the higher part of the section on the Ceiriog 

 conforms to the best types of the Caradoc sandstone, and passes into 

 the system of the Denbigh flags. 4. That the lower Silurian beds 

 in Westmoreland do not conform to the above type : they may be 

 compared with the upper part of the Ceiriog section, and perhaps 

 with the highest part of the Arrenig section ; but they admit of no 

 comparison with the lower and by far the thicker part of the proto- 

 zoic group of North Wales. Lastly, the author, as in a former paper, 

 divides the upper Silurian rocks of Denbighshire, &c. into three pri- 

 mary divisions or groups. The complicated Llangollen sections he 

 puts entirely in the lowest of the three divisions. He confirms his 

 former views by some new details and general remarks, accompanied 

 by lists of fossils. 



Dec. 13, 1843. — The following papers were read : — 



1. " Notes respecting the Coal Measures, Limestone, and Gypsi- 

 ferous Strata of the Island of Cape Breton." By Mr. R. Brown. 



The author gives the details of certain sections in the coal-fields 

 of Cape Breton, confirmatory of Mr. Lyell's views of the relative age 

 of the gypsum and other strata in that island. 



2. " On the lower Carboniferous Rocks or Gypsiferous Formation 

 of Nova Scotia." By Mr. J. W. Dawson of Pictou, Nova Scotia. 



The coal formation of the eastern part of Nova Scotia consists of 

 a great thickness of sandstones, shales and conglomerates of various 

 reddish and gray colours. The lower part of the series is distin- 

 guished by the presence of limestones with marine shells and gyp- 

 sum. In this paper the author examines the structure and relations 

 of the lower or gypsiferous formation, prefacing it with a notice of 

 the general disposition of the rocks of the carboniferous system in 

 the region extending along the shores of the Gulf of St. Lawrence, 

 from Tatmagouche to Antigonish Harbour. The gypsiferous forma- 

 tion is described as met with at East River, Merigonish, Antigonish, 

 and Shubenacardie. The results of Mr. Dawson's inquiries confirm 

 the views advanced by Mr. Lyell in his papers on the geology of 

 Nova Scotia. 



3. " On Concretions in the Red Crag at Felixstow, Suffolk." By 

 the Rev. Prof. Henslow. 



The concretions described are more or less spheroidal, fusiform 

 and cylindrical, many of them amorphous masses of a fine-grained, 

 compact, dark brown ferruginous claystone. Their surfaces are 

 smooth, often polished, and they sometimes include organic remains. 

 Prof. Henslow regards them as of coprolitic origin. Resembling 

 them are certain silicified masses, which prove to be the petro-tym- 

 panic bones of extinct Cetacea ; and Prof. Owen has determined that 



