PLATE LVIII. 



Osteea (continued). 

 Figs. 

 1 — 5. 0. semiplana, Sow. Zone of Belemnitella mucronata, Norwich. (P. 379.) 



1. Sedgwick Museum, a, right valve ; b, anterior view. 



2. Norwich Museum, No. 2129. a, right valve; b, left valve; c, anterior 



view. 



3. Dr. Rowe's Collection. Right valve. 



4. Norwich Museum. One of the types of 0. ahvformis, Woodward (pi. vi, 



fig. 3). a, right valve; b, interior. 



5. Norwich Museum, No. 2085. Right valve. 



6 — 9. 0. sarumensis, Woods. Zone of Actinocamax quadratus, East Harnham. 

 Dr. Blackmore's Collection. G, right valve; 7a, 9, left valves; 

 7b, posterior view of 7a ; 8, right valve. (P. 387.) 

 10—13. 0. incur va, miss. Right valves. (P. 388.) 



10, 11. Totternhoe Stone (zone of Holaster subglobosus) , Burwell. Sedgwick 

 Museum. 



12. Zone of Terebratulina lata, South Devon Coast. Dr. Rowe's Collection. 



13. Zone of Actinocamax quadratus, East Harnham. Dr. Bhickmore's 



Collection. 



