NATURAL HISTORY, TORONTO REGION
very common. The following list gives the commoner fossils :
Ogygites canadensis. Triarthrus beckii.
" spinosus. Lingula cobourgensis. Lingula progne.
Rafinesquina alternata. Diplograptus bicornis.
The Lorraine (Hudson River) shale follows the last formation without a break and extends, as low outcrops, along the shore of Lake Ontario from Toronto to Port Credit. Its best exposures are in the Don Valley brickyard, east of Rosedale, Toronto, along the Humber River south of Lambton Mills, and at a brickyard on the shore of Lake Ontario just west of Port Credit.
The shale is grey and non-bituminous, and at intervals of a foot or two there is a layer of impure limestone, which must be selected out before the shale is ground for brick-making. The limy layers are very fossiliferous, and Professor Parks gives a list of more than sixty species found along the Don and Humber Rivers. The commonest forms are as follows :
Diplograptus pristis. Bythopora delicatula. Dekayella ulrichi.
Rafinesquina alternata. 60