PLATE II. 



Pago 

 Fig. 1. Pachastrella convoluta, Hinde. A large ear-shaped example, showing the upper 



surface. Natural size. From the Upper Chalk at Flamborough, Yorkshire . 26 

 Fig. 1 a. The same. Portion of the outer surface of another specimen from the same 



locality, showing traces of the spicules. Enlarged thirty times. 

 Fig. 2. Seliscuthon planus, Phill. sp. Showing the upper or interior surface of a small 



specimen from the Upper Chalk at Flamborough. Natural size 31 



Fig. .3. The same. Showing the under surface and the stem of the same specimen. 



Fig. 4. The same. A specimen with a nearly plane upper surface. From the Upper Chalk 



at Flamborough. 

 Fig. 5. Seliscothon explanatus, Roemer, sp. Spicules of the interior skeletal fibres. 



Enlarged sixty-four times. From the Upper Chalk at Ahlten, Hanover ... 32 



