370 PROF. S. H. REYNOLDS AND DR. A. VATJGHAN ON [Aug. I9II, 



At Burrington, where large Caninids are absent, it is not easy to 

 distinguish S x from the overlying beds ; the occurrence of Gyrtina 

 carbonaria (M'Coy) is here taken, for convenience, to mark the base 

 of S 2 . The lower limit of S T is also artificial, being taken at the 

 first observation of Lithostrotion. 



The assemblage: — Aihyris inyens (= Athyris cf. glabristria 

 Sibly), Oamarophoria isorhyncha, Carcinophyllimi mendipense, at 

 the base of Quarry 2 suggests the Milton -Road level of Dr. Sibly's 

 Weston paper. 1 [This assemblage is also found at Cheddar, 2 but 

 there the level must be a little higher than at Burrington, for I 

 have found Cyrtina carbonaria to be a common associate of the 

 above-mentioned forms at Cheddar. The distance above the White 

 Oolite in the two cases tends to confirm this view.] 



S 2 : the main Seminula Zone. 



Corals: — 



Cyathophyllum aff. murchisoni E. & H. : an aberrant and rare variant. 

 Lithostrotion martini E. & H. Abundant. 

 Carcinophyllum 9 Vaugban. Common. 



Brachiopods : — 



Productus 9 Vaugban. At tbe bottom. 



Productus corruyato-hemisphericits, including Pr. cora, mut. So, Vaugban. 



Common. 

 Papilionaceous Chonetes. Common. 

 Seminula ficoides Vaughan. Common throughout. 

 Cyrtina carbonaria (M'Coy). Common only at the bottom, but ranges 



through. 

 r.oductus i 



The Seminula fauna is very limited in species, but remarkably 

 abundant in individuals ; bands composed almost entirely of 

 Lithostrotion, Productus, Chonetes or Seminula, succeed each other 

 and repeatedly recur through the zone. Considering how exclusive 

 this fauna is, it is remarkable how widely it is spread, for it is the 

 standard fauna of this period in Belgium and Britain, and we do 

 not yet know its phasal equivalents. 



DlBUNOPHYLLUM ZONE (D). 



J) x : the only part of the zone uncovered at Burrington. 

 Corals : — 



Cyathophyllum murchisoni E. & H. Abundant. 

 Diphyphyllum sp., convergent Koninckophyllum 9 Vaughan. 

 Dibimophyllum (p Vaughan. Common. 



Brachiopods : — 



Productus giyanteus (Mart.), D x mut. 



Productus hcmisphericus J. de C. Sow. Abundant. 



' Orthotetes ' cf. senilis (Phill.). 



Athyris cf. expansa Dav., non (Phill.), mut. Di. 



1 Q. J. G-. S. vol. lxi (1905) p. 560. 



2 Ibid. vol. lxii (1906) p. 357. 



