Geol. Mag. 1912. 



Plate Xl. 



■^ 





2 a ^t'. 



0' 



t 



Si 6 



T. A. Brock del. 



Fig. 1. Dionide atra, Salter, 1866. Upper Arenig : Portmadoe. 

 Figs. 2-6. Ditto. Upper Arenig : near Haverfordwest. 



