294 ON SOME PERMIAN FOSSILS FROM DURHAM. 



of the species. Some of them are more branched, and shoAV a 

 greater aggregation of cells than the one fignred. 



EXPLANATION OF PLATE XIL* 



Figs. 1, 2. Pi'osojnmiscui^ prohkmatk'us^ Schlotli. "J 



sp. Lateral views of anterior portion. From f T.r •,. i- .• 



xV 11 ^ Tj-ii V Ma^nilied ten times. 



Humbletou Hill, C => 



Fig. 3. The same. Dorsal view. J 



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



Quarry. Magnified six times. 

 Fig. 6. Tlie same. Lateral view of posterior ~\ 



portion. f From Field House, Ryhope. 



Fig. 7. The same. Dorsal view of posterior T Magnitied seven times. 



portion. J 



Fig. 8. Chnnnltzia Rocsi<hri^ Geinitz, sp. From Humbleton Hill. IMagnified 



four times. 

 Fig. 9. Chiton Loftusiam/s, King. Lateral view of an^ 



intermediate plate; enlarged. (For comparison with 



fig. 10.) 

 Fig. 10. Chiton HoifAeamif^ Kirkby. Lateral view of an I 



intermediate plate. (Enlarged.) [.From Tunstall Hill. 



Figs. 11, 12. The same. Intermediate plate. (Enlarged.) 

 Fig. 13. The same. Anterior i)late. (Enlarged.) 

 Fig. 14. Ilippothoa Vohjtlana, King, sp. ") Magnitied six- 

 Fig. 15. The same. Side-view. j teen times. 



* This plate corresponds with pi. VII., vol. xiii., of the Quarterly Jonnial of the Geological 

 Societ}' of London, by Avlio-^e obliging permission it appears in these Transactions. 



