PLATE XXXIII. 



Page 

 Fig. 1. Peronella pistilliformis , Lamx. sp. Natural size. From the Great Oolite at 



Hampton Cliff, near Bath J65 



Fig. 1 a. The same. Portion of the outer surface of the same specimen, enlarged fifteen 

 times, showing the irregular apertures between the fibres. 



Fig. 2. Peronella tenuis, Hinde. Natural size. From the Pea-grit beds of the Inferior 



Oolite near Cheltenham \qq 



Fig. 2 a. The same. Portion of a transparent microscopic section of another specimen from 

 the same locality, enlarged seventy-two times, showing the disposition of the 

 spicules of the fibre in the interior of the sponge-wall. 



Fig. 2 b. The same. Showing the disposition of the fibres near the margin of tlie sponge- 

 wall, -with an entire spicule and fragments of others. The fibre is largely 

 crystalline, and only the larger spicules have been preserved. 



Fig. 3. Peronella mamilUfera, Lamx. sp. Natural size. From the Middle Jura, Couche 



h. Polypiers, Ranville, near Caen 1G6 



Fig. 4. Peronella cylindrica, Goldf . sp. A small specimen from the Upper Jura at Randen, 



Switzerland. Natural size 167 



Fig. 5. Peronella ramosa, Roem. sp. Natural size. From the Lower Green Sand at 



Farringdon, Berkshire 1G9 



Fig. 6. Peronella clavarioides, Lamx. sp. Portion of a transparent section of the fibre, 

 enlarged seventy-two times, showing thi'ee- and four-rayed spicules. From the 

 Middle Jura, Couche a, Polypiers at Ranville, near Caen IGC 



Fig. 6 a. The same. Another portion of the fibre, from the same slide as fig. G, showing 

 traces of spicules. 



Fig. 7. Peronella furcata, Goldf. sp. Natural size. From the Cenomanian or Upper 



Green Sand at Essen, Rhenish Prussia 170 



Fig. 8. Peronella proUfera, Hinde. Natural size. From the Lower Green Sand at 



Farringdon, Berkshire 1G9 



Fig. 8 a. The same. Portion of a transparent microscopic section of another specimen from 

 Farringdon, enlarged seventy-two times, showing the relatively wide, radiately 

 crystalline fibre, with traces of small three- and four-rayed spicules. The greater 

 portion of the spicular structure in this specimen has been obliterated. 



Figs. 9-9 b. Peronella ocellata, Hinde. Three examples of this species, natural size, from 



the Upper Chalk at Maestricht 171 



Fig. 9 c. The same. A portion of the outer surface of 9 6, enlarged fifteen times, showing 

 the large circular and the small irregular apertures of the dermal layer. 



Fig. 10. Peronella Gillieroni, de Loriol, sp. Natural size. An imperfect specimen from 



the Lower Green Sand at Farringdon 169 



Fig. 11. Elasmocwlia crassa, From. Natural size. From the Lower Green Sand at 



Farringdon, Berkshire 176 



Fig. 12. Amphispongia oblonga, Salter. Natural size. Showing the interior of a split 

 specimen of an unusually large size, surrounded by the rocky matrix. In the 



