Dr. Wheelton Hind — Lower Culm of North Devon. 401 



« passage from Devonian rocks into Carboniferous without a strati- 

 :graphical break. Curiously enough, beds with a Devonian fauna, 

 CuGullcea unilateralis and Ptychopteria Damnoniensis, which in Devon- 

 shire are recognised as the Gucullcea beds and occur below the Pilton 

 Beds, are classed as Carboniferous in Ireland. It appears to me 

 that a similar sequence occurs in both South- West Cork and Kerry 

 and Devonshire. The Coomhola grits with Cucullcea unilateralis and 

 Ptychopteria Damnoniensis, are the equivalents of the Pickwell Down 

 and Baggy Point Beds, and the beds with P. Becheri, the equivalents 

 of the Venn Limestone series of the Lower Culm. It would be well 

 if stratigraphical lines, based on palaeontology, were identical in 

 the two countries. The fauna of the Coomhola grits is typically 

 Devonian, and not Carboniferous. The absence of Carboniferous 

 Limestone in North Devonshire and further west along the line of 

 strike, at Old Head of Kinsale and the part of Ireland west of that 

 point, shows that this absence in both localities is due to the same 

 •conditions of deposit. The succession in both countries is the same. 

 Devonshire. South-West Ireland. 



Lower Culm ... ... Fosidonomya heds, Tendleside series, 



Pilton Beds ... ... Coomhola ojrits ) tt t^ 



Baggy Beds Cucullcea zone ) Upper Devoman. 



The absence of Carboniferous Limestone in both areas is very 

 definite, and the recognition that the sequence in North Devon and 

 South- West Ireland is identically the same not only broadens the 

 question, but at the same time demonstrates that the Culm of 

 Devonshire is not merely a local condition, and that the absence of 

 Carboniferous Limestone in South- West Cork and in the Carboniferous 

 series of Devonshire is due to the same series of causes. 



Pseudamnsium fihrillosum. — This species is, as far as I know, 

 never found below the Pendleside series, but it passes up into 

 Ooal-measures. This is an important species, because it has been 

 obtained from the Culm of Herborn and Magdeburg. For the 

 synonymy of this species vide my monograph on British Car- 

 bonifex'ous Lamellibranchs, vol. ii, p. 106. 



Glyphioceras spirale. — This species is very plentiful, occurring in 

 thousands, in a blackish shale about 500 feet below the third grit 

 at Congleton Edge, Cheshire. I have found it at various other 

 localities in Yorkshire, but I always consider that it denotes a zone 

 higher up in the series than that of P. Becheri. The species appears 

 to be more common in South Devonshire than in the north of the 

 country, and I can say nothing definitely about its actual position in 

 the series there, but it is stated that it occurs with Posidonomya, 

 Ussher, " British Culm Measures," Somerset Arch, and Nat. Hist. 

 Soc, vol. xxxviii (1892), p. 132; he says, "The Posidonomya in 

 these beds are, as a rule, smaller than those occurring in the beds 

 which in the Chudleigh and Bovey Tracey districts carry on the 

 ■calcareous horizon." In Cheshire G. spirale occurs with Posidoniella 

 Icevis. The other Goniatites found in the Becheri beds are not typical 

 of the horizon, for they occur at various horizons in the Carboniferous 



