56 THE CARBONIFEROUS LIMESTONE OF SOUTH-WEST GOWER 
Note, — Seminula ambigua, niut., and Carcinophyllum 6 occur in 
the upper part of the sub-zone as they do elsewhere. 
Athyris sp. is a form that occurs in S 2 at Lydstep (near 
Tenby), Burrington and Weston. 
DIBUNOPHYLLUM ZONE D, AND D2. 
Di is characteristically developed in the Porteynon 
Section. 
Fauna — 
Productus ‘ giganteus.^ 
Productus hemisphericus. 
Syringopora cf. ramulosa, Syr. cf. geniculata and 
Syr. sp. 
Cyathophyllum Murchisoni (abundant). 
Lithostrotion Martini. 
Campophyllum sp. 
Dibunophyllum B (common). 
D2 forms the upper part of the Porteynon Section 
Fauna — 
Productus sp. 
Lithostrotion Portlocki. 
Lith. irregular e and var. (abundant). 
Lith. junceum (common). 
Lith. Martini (Koninckophyllid, mut.), (common). 
HORIZON e. 
This horizon is not represented by any of the fossils in 
Dr. Gubbin’s collection ; the highest beds he mentions 
contain abundant Lith. irregulare, and must be referred 
to D^. 
