PLATE XX. 



Page 

 Fig. 1. Ragadinia sulcata, Hinde. An imperfect specimen inclosed in a flint from the 



Upper Chalk at Bcckhampton, Wiltshire. Natural size 83 



Fi". 1 a. The same. Portion of the outer surface of another specimen in which the dermal 



layer has been preserved, showing its component spicules. Enlarged thirty-two 



times. 

 Fig. 2. PUnthosella squamosa, Zitt. Natural size. From the interior of a flint. The 



spicular structure has been completely dissolved, and only the empty vermi- 



culate moulds of the spicules remain. Presented to the Museum by Mr. H. J. 



Carter, P.R.S 85 



Fig. 3. PUnthosella compacta, Hinde. Natural size. Preserved in the interior of a flint 



from the Upper Chalk of Wiltshire. The specimen belongs to the Jermyn- 



Street Museum 85 



Fig. 3 a. The same. Portion of the outer surface of the same specimen, enlarged thirty-two 



times, showing the spicular structure. 

 Fig. 4. PUnthosella nodosa, Hinde. A specimen inclosed in a flint from the Upper Chalk 



of Wiltshire. Natural size. The specimen belongs to the Jermyn-Street 



Museum 86 



Fig. 4 a. The same. Portion of the outer surface of the same specimen, showing the spicular 



scales of the dermal layer. Enlarged thirty-two times. 

 Fig. 5. Pholidocladia dichotomus, Hinde. An imperfect specimen preserved in a flint from 



the Upper Chalk of Wiltshire. Natural size. The specimen belongs to the 



Jermyn-Street Museum 81 



Fig. 5 a. The same. Portion of the outer surface of a branch of fig. 5 where the dermal 



layer is absent, showing the spicular structure of the interior skeleton. Enlarged 



sixty-four times. The square beneath the figure represents its natural size. 

 Fig. 5 b. The same. Portion of the outer surface of another branch of fig. 5, on which the 



dermal layer has been retained, showing its component spicules. Enlarged 



thirty-two times. 



