Notices of Memoirs — The British Association. 561 



Ca'pe Breton. — The coal-field is Carboniferous, the measures con- 

 sist of an accumulation of sti'ata, comprising shale, sandstone and 

 fire-clay, with numerous valuable seams of bituminous coal. The 

 principal field is about thirty-one miles long, bounded on the north 

 by the ocean, on the south by the Millstone Grit, the outcrop of the 

 seams are found on the shores of the deep bay. The measures lie 

 at an easy angle, dipping under the sea. 



Pictou County has the next important field, and is widely known 

 on account of the immense thickness of the seams, they are more 

 irregular in their dip than those of Cape Breton, with an angle from 

 10° to 30°. The total area is about thirty-five square miles, but 

 owing to the extent of faults, a large portion of the coal is cast off, 

 the whole field forms an irregular basin, let down on all sides, among 

 rocks of older age. 



Cumberland County. — This important field has only recently been 

 developed on a large scale, the productive measures extend from the 

 Jnggins, on the shore of the Bay of Fundy, for more than twenty 

 miles easterly, towards the base of the Cobequid Hills. On the 

 shore of the Bay of Fundy, the exposui-e is of immense thickness, 

 estimated at 14,000 feet, extending from the Marine Limestones of 

 the Lower Carboniferous to the top of the Coal formation. Its 

 extent has not yet been arrived at. 



North- West. — The ninety-seventh meridian separates pretty 

 exactly the coal-bearing formations of America into two classes. 

 To the east. Carboniferous ; in the west, the coal and lignites are 

 found at various horizons in the Secondary and Tertiary rocks ; their 

 development has only commenced ; but when it is considered that 

 outcrops of valuable seams are found eastward of the Eocky 

 Mountains, from the United States boundary, for hundreds of 

 miles to the north, no anxiety need be felt as to their extent. 



British Columbia. — Very little exploration has been made in the 

 mainland, the coals of Vancouver Island being easily accessible and 

 of excellent quality. The best-known fields are those of Comox and 

 Nanaimo, on the eastern shore of the Island. The measures dip 

 mostly under the sea ; they are variable, however, and require the 

 diamond drill to be used extensively ; the coals are bituminous and 

 are considered the best on the American Pacific Coast. Two 

 companies, the Wellington and Vancouver, work extensive mines. 



-A Pkeliminaky Examination of the Siliceous Organic Eebiains 

 IN THE Lacustrine Deposits of the Province of Nova Scotia, 

 Canada. 



By Alexander Howard Mackay, B.A,, B. Sc. 



ANY of the lakes of Nova Scotia contain large deposits abound- 

 ing in these remains, which consist of the siliceous skeletons 

 of upwards of sixty species of Diatomacese, and of the siliceous 

 spicules of at least seven species of fresh-water sponges. The 

 deposits from different lakes are generally marked by a difference in 

 the species present or in their relative proportion. In lakes which 



decade hi. A'OL. I. — NO. XII. 36 



