T1IK CRETACEOUS SYSTEM 513 



ilic Micraster zones of the English Chalk ; the whole of the Middle 

 Chalk and perhaj)8 that of Hoi. planus also being absent 



Above the "Chloritic chalk" is the "White Limestone," which 

 has a bed of nodular chalk at its base containing Act. verug and 

 many sponges, and in the north of Antrim a similar nodular bed 

 is succeeded by 5 feet of flintless chalk containing plates of 

 Marsupites. Finally in conformable succession is white chalk 

 with many flints, about 100 feet thick, having Act. quadratus 

 near the base and Bel. mucronata in the higher part. 



Scotland. Cretaceous rocks are found again especially on the 

 \\vst coast of Scotland, in the island of Mull and in the 

 district of Morvern on the adjacent mainland ; as in Ireland, they 

 belong exclusively to the upper division of the system, and though 

 they can be correlated generally with the Irish Series, they exhibit 

 a still more abnormal fades and a more decided approach to littoral 

 conditions. They are best exposed in Morvern, along the shores of 

 Loch Aline, and beneath the singular outlying masses of Beinn-y- 

 Hun and Beinn-y-Hattan. 2 " The general succession here is : 



Feet. 



4. Sandstones and white marls with plant remains (high 



Cretaceous or early Eocene) ...... 20 



3. White indurated chalk with bands of flints, Belemnitella 

 mucronata, and fragments of Inoceramus ; some beds of 

 glauconitic chalk at the base ...... 10 



2. White sandstones without fossils, but containing a thin seam 



of coal 30 to 100 



1. Glauconite sands, passing sometimes into dark-green argil- 

 laceous sand, sometimes into calcareous sandstone ; Pecten 

 asper, P. orbicularis, Exogyra conica, but no Ammonites 20 to 60 



On comparing these beds with those of Antrim we may safely 

 regard No. 1 as equivalent to Nos. 1 and 2 of the Irish sequence. 



The overlying white sandstones (No. 2) would appear to be 

 homotaxial with the zone of Ostrea columba in Ireland, whatever 

 the precise age of that may be. Above it there is a palaeontological 

 break, though apparently no unconformity, and the hard white 

 chalk corresponds closely to that of Ireland, except that there is no 

 sign of the Micraster zone at its base. 



D. CONTINENTAL REPRESENTATIVES 



1. Northern France 



In France the Cretaceous exhibits two very different facies, 

 that of the southern provinces being very different from that of 

 the northern region, which is often called the Paris basin. The 

 deposits found in the latter closely resemble those of England, and 



2L 



