106 J. E. Man- — The Coniston Limestone Series. 



and myself, we compared the Eoman Fell Beds with the Beyricliia 

 Limestone of Scandinavia and the Trenton Limestone of North 

 America, and suggested their correspondence with the Ardwell Beds 

 of the Girvan area. The peculiar fauna will probably be discovered 

 elsewhere, and should be searched for amongst the shales below the 

 Bala Limestone of North Wales, and among the fossiliferous beds of 

 Tyrone. 



The well-known fauna of the Sleddale Group ' has been 80 

 frequently and successfully compared with the similar fauna of the 

 Bala Limestone, and its equivalents in the British and foreign 

 Lower PalaBozoic areas, that it is unnecessary to discuss the identity 

 in this place, for it is now generally recognized. The relationship 

 of the Dul'ton Shales to the Trimicleus Shales on the one hand, and 

 the normal Sleddale Beds on the other, has also been commented on 

 in a previous communication. The very abrupt change from the 

 Lake District type of the Sleddale Group to the Cross Fell type in 

 the short interval occupied by the newer beds of the Eden Valley, 

 is a point that requires notice. I have already remarked on the 

 likeness of the Keisley Limestone to that of the Chair of Kildare. 

 A re-examinatiou of the Bala Beds of Kildare and Tyrone is very 

 desirable, as several stratigraphical horizons appear to be represented 

 there, judging from the fossils which have been obtained. 



The equivalents of tlie Staiirocephalus Limestone occur in many 

 parts of Britain, as well as in Scandinavia. Indeed, it is at first 

 sight surprising to find how constant are the lithological characters 

 of this green argillaceous limestone, when we remember that it is 

 seldom more than a few feet in thickness. It retains its peculiar 

 character in the south of Scotland (the "Starfish-bed), North Wales 

 (Rhholas Limestone), Pembrokeshire (Stauroccphalus Limestone), 

 Ireland, and Scandinavia. 



An examination of the fauna fully accounts for this constancy 

 of character. Though it contains many species common to the 

 overlying Ashgill Shales, there is a marked change betwixt the 

 organisms of this limestone and those of the underlying Sleddale 

 Group, and very few species are common to the two. Insignificant, 

 therefore, as the thickness of this deposit is, the time taken for its 



^ It may be remarked that sufficient proof has not been offered as to the distinct- 

 ness of the Stile End Beds from the Corona Beds of the Cross Fell area. The 

 somewhat meagre list of Stile End fossils previously given does not bring out the 

 marked contrast between these beds and those of the Koman Fell Group. Not only 

 is the peculiar fauna of the Corona Beds entirely absent from the Stile End deposit 

 (and fossils, though ill-preserved and belonging to few species, are very abundant at 

 Stile End), but the Stile End rocks are crowded with casts of Lindstrwrnia, both iu 

 the region where the Yarlside rhyolite separates them from the Applethwaite Beds, 

 and in the region further west. No Lindstrocmia has yet been detected in the 

 Eoman Fell Beds. In the neighbourhood of Coniston the Stile End Beds contain 

 numerous fossils, which, as is usual with the beds of this series, are preserved as 

 casts only, but fragments of several fossils generically identical with those of the 

 Applethwaite Beds are easily discoverable, and, as far as one can judge, they are 

 also specifically identical. Though it is just possible, therefore, that these Stile 

 End Beds are actually representatives of the lloman Fell Group, all the evidence 

 points to their being newer. 



