218 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. fJail. 21. 



My specimen is not much branched ; and the branches always 

 arise from the anterior portion of the cell at an obtuse angle. 



This fossil is undoubtedly a Bryozoon ; and, as the genus Aulo- 

 pora is stated by MM. Edwards and J. Haime to be only the young 

 stoloniferous base of a Syringoporay I have, after an attentive ex- 

 amination of its affinities to existing genera, placed it in the species 

 Hippothoa, to which it bears a strong resemblance and an evidently 

 close relation. 



The specimen figured is from Tunstall Hill, and is attached to 

 the external surface of a Terehratula elongata. 



EXPLANATION OF PLATE VIL 



Magnified ten times. 



Figs. 1, 2. Prosoponiscus problematicus, Schloth. sp. 

 Lateral views of anterior portion. From Hum- 

 bleton Hill. 



Fig. 3. The same. Dorsal view. 



Figs. 4, 5. The same. Lateral views of posterior portion. From Humbleton Quarry. 

 Magnified six times. 



Fig. 6. The same. Lateral view of posterior portion. "1 From Field House, Ryhope. 



Fig. 7. The same. Dorsal view of posterior portion, j Magnified seven times. 



Fig. 8. Chemnitzia Roessleri, Geinitz, sp. From Humbleton Hill. Magnified 

 four times. 



Fig. 9. Chiton Loftusianus, King. Lateral view of an inter-" 

 mediate plate ; enlarged. (For comparison with fig. 10.) 



Fig. 10. Chiton Howseanus, Kirkby. Lateral view of an inter- 

 mediate plate. (Enlarged.) S. From Tunstall Hill 



Figs. 11, 12. The same. Intermediate plate. (Enlarged.) i^ *rom iunsiau nm. 



Fig. 13. The same. Anterior plate. (Enlarged.) 



Fig. 14. Hippothoa Foigtiana, King, sp.T Magnified sixteen 



Fig. 15. The same. Side-view. / times. 



