IN THE ANGLO-PARIS BASIN 129 



in Greenland is not yet clear. In a similar manner the primitive Arctic Ocean may 

 have formed the northern boundary, for Hoplites is not yet known from Canada, 

 Alaska or Japan. The province, therefore, consists of the shelf seas of Europe. In 

 the lyelli Subzone especially, there are important links with adjoining ammonite 

 faunal provinces in which Hoplites (H.) is as yet unknown. These links are discussed 

 in greater detail below. 



(b) The Zone of Euhoplites loricatus 



This Zone comprises the Subzones of A. intermedins, D. niobe, M. subdelaruei and 

 E. meandrinus. It is almost the total range of E. loricatus which is typical of the 

 group of Etihoplites with sulcate rather than channelled venters seen late in the lautus 

 Zone. Deposits of this Zone, with the exception of the basal part of the intermedins 

 Subzone, are of very limited occurrence in the European province. This is probably 

 due to erosion in the early part of the Upper Albian which apparently produced a 

 fairly general hiatus involving the loricatus and lautus Zones throughout much of 

 Europe except in the deeper basins. It could be argued that there is no point in 

 dividing Jukes-Browne's original lautus Zone into two parts, but the morphological 

 change in Euhoplites is quite striking at the level at which the writer has drawn the 

 base of the lautus Zone. Although the change in the remainder of the ammonite 

 fauna is not quite so clear cut, nonetheless it does occur at about the same point in 

 time. The ammonite fauna of the loricatus Zone is grosso modo sufficiently distinct 

 for it to be capable of definite recognition at zonal rank. Spath placed the division 

 between the dentatus and lautus Zones in his sense at the top of the niobe Subzone 

 where in fact there is no significant change in the ammonite fauna. This quite 

 arbitrary and meaningless arrangement is firmly rejected here. 



The intermedins Subzone has as great a geographical range as the spathi Subzone 

 of the dentatus Zone but known sediments of the niobe, subdelaruei and meandrinus 

 Subzones are preserved in only a very limited area, that of eastern England and 

 northern France. Links with other ammonite faunal provinces are very few and 

 mainly with the tethyan belt. 



(c) The Zone of Euhoplites lautus 



The lautus Zone as now defined consists of two Subzones ; that of Euhoplites nitidus 

 and that of Anahoplites daviesi. It is essentially the total range of Euhoplites lautus, 

 and the contemporary species of this genus with their well-marked clean cut ventral 

 channel. The base of the Zone as indicated above is defined by the quite sudden 

 change in the peripheral aspect of Euhoplites. The top is defined by the appearance 

 of Dipoloceras bouchardianum and Beudanticeras beudanti indicating the base of the 

 cristatum Subzone. 



Deposits of the nitidus Subzone are of very limited known geographical extent. 

 They are known from eastern England and northern France, and apparently occur 

 also in Poland, but these are probably only remnants which survived the basal Upper 

 Albian erosional movements. The daviesi Subzone can definitely be identified in 

 Russia (Mangyshlak Peninsula) but this is the only area outside the eastern Weald of 

 England that deposits of this Subzone have as yet been recognised. Russian 



