1863.] DAVIDSON NOVA-SCOTIAN BRACHIOPODA. 159 



Localities: — Cumberland, north of the Cobequid Mountains; 

 Northern Colchester, Pictou ; well exposed on the Joggins coast, and 

 on the coast of Northumberland Straits, west of Pictou Harbour. 



Loiver or Older Coal- formation. 



Grey and dark-coloured sandstones and shales, with a few reddish 

 and brown beds ; valuable beds of coal and ironstone ; beds of bitu- 

 minous limestone, and numerous under- clays with Stigmaria. Thick- 

 ness, 4000 feet or more. 



Fossils : — Stigmaria, Sigillaria, Lepidodendron, Poacites, Calamites, 

 Ferns, &c, erect Trees in situ, remains of Ganoid Fishes, Cypris, 

 Modiola, and three species of Eep tiles. 



Localities : — Cumberland, north of Cobequid Mountains, Pictou, 

 especially East Eiver, Port Hood, Inhabitants' Basin, and other 

 places in Inverness and Richmond ; eastern part of Cape Breton ; 

 parts of Colchester, south of Cobequid Mountains. The finest ex- 

 posures are in the South Joggins, and near Sidney, Cape Breton. 



Lower Carboniferous or Gypsiferous Formation. 



Great thickness of reddish and grey sandstones and shales, espe- 

 cially in the upper part ; conglomerates, especially in the lower part ; 

 thick beds of limestone (with marine shells) and of gypsum. Thick- 

 ness, 6000 feet or more. 



Fossils: — Productus, Terebratula, Encrinites, Madrepores, and 

 other marine remains in the limestone. Coniferous wood, Lepido^ 

 dendron, Poacites, &c, in the shales and sandstone. Scales of Ganoid 

 Fishes very abundant in the shales associated with the lowest beds, 

 in which are also coaly seams and bituminous beds. 



Localities : — Northern Cumberland, Pictou, Colchester, and Hants; 

 Musquodoboit, in Halifax county; Guysboro (in part), parts of Inver- 

 ness, Richmond, Cape Breton, and Victoria. 



All the Brachiopoda, with one exception, are stated to have been 

 derived from the Lower Carboniferous or Gypsiferous formation; 

 and, although the fossiliferous rocks submitted to my examination 

 vary considerably in composition and texture, it is evident that the 

 larger number of the species continued to live together for a con- 

 siderable period of time. There is a compact, light-yellowish-grey 

 limestone, full of Spirifera glabra, Terebratula saecidus, Productus 

 Cora, &c. ; while some limestones, with the same fossils, are almost 

 black in colour; others are arenaceous, yellow, and full of small 

 cavities, the interior of the shells being often hollow ; and, again, 

 other limestones, as that of Brookfield, are formed almost entirely of 

 shells, Bryozoa, &c, so closely packed that there appears in some 

 cases to be hardly any cementing material or intervening matrix. 

 Some shales also contain flattened valves of Streptorhynchus crenistria. 

 Dr. Dawson believes that this remarkable lithological difference in 

 the Lower Carboniferous rocks of Nova Scotia may have been caused 

 through the limestones having been deposited in limited basins or 

 narrow straits, and probably at a time of much volcanic disturbance ; 



