626 FAUNAL SUCCESSION OF THE UPPER BERNICIAN 



Alveolites septosa conspicuous but not abundant. Semlnula 

 ambigua and other small brachipods common. Producti un- 

 common ; the strong ribbed P. latisswms occurs. Edmondia 

 sulcata very plentiful. 



Fatinal List. 



Alveolites septosa (Flem.) 

 Fenestella 



Seminula ambigua (Sow.) 

 Productus latissimus, Sow, coarsely 

 ribbed. 



Productus giganteus var, nov. or 



abnormal form 

 Productus longispinus, Sow. 

 Lithodomus jenkinsoni {M'Coy)f 

 Edmondia sulcata (Flem.) 

 Bellerophon sp. 



Notes. — The Alveolites is found as small tumulary masses. 

 The bed needs more investigation. 



The Thornbrough Limestone. 



Geographical Distribution. 



Exposed in the north bank of the Tyne near Styford Hall, 

 the limestone occupies a wide outcrop at Thornbrough to 

 the east of Corbridge, and has been traced northwards by 

 Stamfordham, through Belsay Park to a point beyond the 

 river Blyth. The Stanton Limestone on the east of the 

 village of that name is a continuation of the Thornbrough 

 Limestone. 



Stratigraphical Character. 



This limestone retains for a distance of 19 miles the 

 character it possesses at Styford, where a thick black shale is 

 seen sandwiched between the two beds of limestone. Total 

 thickness (average) about 18 or 20 feet. Central shale 

 thickest at Styford and Stanton — the two extremities. 



Faunal Diagnosis. 



Corals. — Dibuiiophylluni nmirheadi and Cyclophyihini afF. 

 pachyendothecujn plentiful ; Lithostrotion rare or absent. 



Brachiopods. — Productus latissimus Sow. and latissimoid 

 Producti {Prod. /B and var.) abundant ; P. muricatus plentiful ; 

 P. scabriculus common. 



t Halton Shields. 



