86 SHELVE DISTRICT 



margin, adductor muscle field extending anterior of dorsal umbo for almost three- 

 quarters the length of the valve. 



Type material. 



length width (mm) 



Holotype Internal mould of brachial valve (BB 35387) 17 3-0 



Paratypes External and internal moulds of brachial valve 



(BB 35388a, b) 1-3 2-6 



Incomplete internal mould of pedicle valve 



(BB 35389) _ 



Incomplete internal mould of brachial valve 



(BB 35390) 1-2 



Incomplete external mould of brachial valve 



(BB 35391) 



Incomplete internal mould of brachial valve 



(BB 35392) o-8 



Incomplete internal mould of brachial valve 



(BB 35393) i-i 



External and internal moulds of brachial valve 



(BB 35394a, b) 1-6 



External and internal moulds of pedicle valve 



(BB 35395a, b) i-i 2-0 



Internal mould of brachial valve (BB 35396) 1-9 - 



External and internal moulds of brachial valve 



(BB 35397^, b) i-6 



External and internal moulds of brachial valve 



(BB 35398a, b) 1-5 



External and internal moulds of brachial valve 



(BB 35399a, b) 17 - 



External and internal moulds of brachial valve 



(BB 35400a, b) 2-0 



External and internal moulds of brachial valve 



(BB 35401a, b) 0-9 17 



Horizon and localities. Mytton Flags : BB 35387 to 35393, BB 35398, 35399 

 from a trench excavated in Shelve Church Beds (Grid Ref. SO 335990) ; BB 35394 

 to 35397 from exposures of Shelve Church Beds along a cart-track near Wood House, 

 Gravels (Grid Ref. SJ 338003) ; BB 35400, 35401 from Shelve Church Beds exposed 

 along a cart-track 50 yds north-west of Wood House, near Gravels (Grid Ref. 



SJ 337002). 



Discussion. The moulds of the new species that have been collected are so 

 closely crowded and so commonly collapsed that only a few statistical data were 

 obtainable to indicate the variability of the new species. These are included in the 

 description given above. 



