CHAP. VI.] CARBONIFEROUS PERIOD. 75 



We have now traced indications of the existence of a 

 coast-line all the way from Wexf ord and Waterford to the 

 north of County Down, and here we are, doubtless, not far 

 from its northern limit, for there can be little doubt that 

 there was a connection between the Irish and Scotch waters 

 at this period. The rocks of County Down are evidently a 

 continuation of the Silurian and Ordovician tracts of 

 southern Scotland, and it is highly probable that in early 

 Carboniferous times they formed one continuous mass of 

 land, and it is not at all improbable that this land included 

 the northern part- of the Isle of Man. It is true that there 

 is carboniferous limestone at the southern end of the Isle 

 of Man, but there is no proof that it ever extended far to 

 the north, and the red sandstones and cornstones of Peel 

 may be shore-beds of the Limestone sea, like the red sand- 

 stones of Scotland. 



That this was the case on the northern border of the 

 land area we are now considering is the decided opinion of 

 the Geological Surveyors of Lanarkshire. Describing the 

 basal conglomerates of this district, they say: "These con- 

 glomerates continue to fringe the Carboniferous area, while 

 the strata above pass quite away. Hence, in this con- 

 tinuous band of conglomerate, one portion is on the horizon 

 of a low part of the Calciferous Sandstone series, while 

 another portion is on the horizon of the Carboniferous 

 Limestone series. It thus brings before us evidence of 

 shore conditions during a protracted submergence of this 

 area in Lower Carboniferous times." 1 It must be remem- 

 bered, also, that what is here called the Calciferous Sand- 

 stone is now regarded as contemporaneous with the lower 

 part of the English Carboniferous Limestone. 



Eeturning to the Isle of Man, the existence of the Lime- 

 stone series there is no proof that there was open sea to the 



1 " Mem. Geol. Surv. of Scot., Expl. Sh. 15," p. 30. 



