126 C. Edmonds — 



laid down almost equal in thickness to the corresponding beds of 

 our area. 



(3) That the Fell Top Limestone of the Alston area was deposited 

 in a depression running from 'Alston Moor to Alnwick long after 

 "Millstone Grit" conditions bad succeeded to our First Limestone. 



(4) And finally, that during the deposition of the limestones of the 

 upper portion of the series the conditions were so uniform as to 

 allow the accumulation of beds which are recognizable over an 

 area stretching from West Cumberland to the North-East of 

 Northumberland. 



COREELATION WITH OtHER ArEAS AND ZoNAL CLASSIFICATION. 



Fig. 3 gives the correlation of our series with those in several 

 areas in various parts of Britain. I have adopted the table published 

 by Garwood in his North-Western Province paper (p. 547). only 

 substituting more recent names for one or two of the index-corals 

 mentioned by him. As will be seen from Fig. 3 he groups the 

 Great Limestone with Dg. On the other hand, in Figs. 1 and 2, 

 following Dr. Stanley Smith,^ I have indicated that it may possibly 

 be part of Dg, his correlation being supported by the occurrence in 

 this limestone of a highly specialized sub-species of Lonsdaleia 

 floriformis Mart., which he has named Lonsdaleia flor if ormis laticlavia, 

 and which is not known from any lower horizon. The sub-species 

 characteristic of the " Lonsdaleia Beds " of Garwood is evidently 

 from the figure,^ Lonsdaleia floriformis (Mart.) mut. crassiconus 

 S. Smith. 



Summary. 



The examination of the fossil fauna, the chief forms of which are 

 shown in Tables I and II and Fig. 1, shows that the beds commence 

 at a high horizon of the Seminula Zone and extend to the top of 

 the Dibunophyllum Zone. Also, the " life-zones " established by 

 Professor Garwood in his North-Western Province Paper can be 

 readily recognized in our area and the series includes the sequence 

 from the Nematophyllum minus sub-zone of the Prodiictus corrugato- 

 Tiemisphericus Zone to the Dibunophyllum muirheadi sub-zone of 

 the Dibunophyllum Zone. It can further be established that the 

 limestones of our area do not persist up the horizon of the Botany 

 Beds with Aulina rotif ormis S. Smith. The Saccammina Band 

 occurs in our area, but Saccammina occurs also in the limestones 

 immediately above and below. The Girvanella Band of the 

 North- West Province has been recognized and forms a constant 

 horizon throughout the area. It occurs associated with a calcite- 

 mudstone and never as a nodular bed. Other bands also appear to 

 be algal. The Spiriferina cf. laminosa Band of Garwood forms a 

 constant horizon between the Seventh and Sixth Limestones. 



1 " The Faunal Succession of the Upper Bernician " : Trans. Nat. Hist. 

 Soc. Northumberland, etc., n.s., vol. iii, 1910, p. 591. 



2 E. J. Garwood, Proc. Geol. Assoc, vol. xxvii, 1916, pi. xvii, fig. 1. 



