FAUNAL SUCCESSION OF THE UPPER BERNICIAN 



603 



Wark and turn northwards. Their course being checked by a 

 fault west of Sweethope Lough, they and their associated beds 

 occur as faulted outliers among the Carbonaceous strata to 

 the northward. 



Redesdale Ironstone Shale. 

 Redesdale. 

 Stratigraphical Character. 



Thickness about 30 feet. This shale is separated from the 

 Redesdale Limestone by a thin but variable layer of black 

 shale (1-2 feet) and a thin bed of sandstone, about 5 feet. 

 The Ironstone Shale consists of a black argillaceous deposit 

 with numerous bands of ironstone nodules and a layer of clay 

 ironstone (4-6 inches). 



Faunal Diagnosis. 



Corals : — Corals exceedingly rare, except Alveolites. 



Brachiopods : — Productus ttndatiis and Lingula scotica char- 

 acteristic forms. P. concinnus and Orbiculoidea nitida very 

 abundant. 



Lamellibranchs : — This class is represented by a large 

 number of species ; the most plentiful forms being Schizodus 

 axiniformis and Nucula gibboSa. 



Fatmal List: — 



Dibunophyllum near 0, Vaughan. 

 Fistulipora incrustans, Nich. and 

 Foord. 

 Alveolites. 



Ceriopora interporosa (Phill.) 

 Heterotrypa tumida (Phill.) 

 Fenestella. 



Seminula ambigua (Sow.) 

 Dielasma gillingensis (Dav.) 

 Spiriferina cf. laminosa (M'Coy.) 

 Martinia glabra (Mart.) 



Reticularia lineata (Dav.) 

 Pugnax pleurodon /? (Phill.) and 



young forms of P. pleurodon. 

 Orthid. 

 Orthotetid. 



Leptssna analoga(PhiIl.)var. distorta 

 (Sow.) 

 Productus corrugatus, M'Coy. 

 Productus corrugato-hemisphericus 

 Productus antiquatus, Sow. 

 Productus pugilis, Phill. 



