Hind: Life Zones tn British Carboniferous Rocks. 
The Derdva is very large and very common in the lower 
beds of the quarry. Casts show very beautifully the internal 
structure of the shell and the centre plates which distinguishes 
this genus from Orthotefes. 
At Hazel Hill, in the parish of Sawley, near Ripon I 
obtained 
Productus cora, a late mutation. 
Ae longispinus. 
Chonetes, sp. laguessiana. 
Derbya sp. 
Schizophoria resupinata. 
Lamellibranchiata. 
Aviculopecten dissimtlis. 
si stellarts. 
a5 semtcostatus. 
Pterinopecten whitet. 
Edmondia maccoyt?. 
Ae rudts 
Letopteria sp. 
Lithodomus genkinsont. 
Mytilimorpha sp. 
Parallelodon sp. 
Paleolima sp. 
Protoschizodus curtus. 
Sanguinolites sp. 
Tellinomorpha cunetformts. 
Gasteropoda. 
Macrocheilina sp. 
Naticopsis sp. 
Euphemus sp. 
Cephalopoda. 
Stroboceras sulcatum. 
Epipphioceras bilobatum. 
Orthoceras sp. 
This fauna is a remarkable one to find so high up in the 
Carboniferous series. Possibly the shell bed on Pule Hill may 
represent it. A very large number of species are of Lower 
Carboniferous forms which do not appear in British strata, as 
far as we know, in the 2000 feet of rocks immediately below. 
It would be interesting to know where they were living in the 
meanwhile. The fauna indicates much clearer waters during 
the period in which the shell bed was laid down than the 
characteristic fauna of the Millstone Grit. 
In North Staffordshire a marine band with Gas¢rioceras 
listert, Pterinopecten papyraceus, and Posidontella laevis always 
underlies the rough rock or Roches Grit. Workings to reach 
the coal on the Grit below turn out a shale rich in com- 
pressed specimens and fragments of these fossils in the 
neighbourhood of Ipstones and Oakamoor. The fauna is found 
in shales below the first Grit at Knypersley. 
Mr. Spencer’s experience in Yorkshire is very similar, and 
we may consider it a fact that the abundance of Gas/rioceras 
/istert increases at higher horizons in the Millstone Grit until a 
maximum is reached in the Bullion, Mountain-mine, or Hard 
Bed Coal of the Halifax district. 
At Caton Green, a few miles from Lancaster, in the Lune 
Valley, a series of shales below some grits have been worked 
1907 March 1. 
