PLATE XXXIX. 



Pecten {continued). 



Figs. 



1 — 5. P. (Neithea) atavus, Rom. Lower Greensand, Upware. 1, 5, Mr. J. F. 

 Walker's Collection. 2, 3, 4, Woodwardian Museum. (P. 197.) 



1, right valve. 2, left valve. 3 a, right valve; 3 b, posterior view of both valves. 

 4 a, right valve ; 4 b, portion between the two middle ribs of left valve X 3 ; 

 4 c, portion between the two middle ribs of right valve x 3. 5, portion 

 between the two middle ribs of right valve x 4. 



6 — 10. P. (Neithea) cometa (d'Orb.). Upper Greensand, Warminster. (P. 200.) 



6. British Museum, No. 38267. Eight valve. 



7. Woodwardian Museum, a, right valve ; b, posterior view of the same ; c, anterior 



view of same. 



8. British Museum, No. 88871. Left valve. 



9. Museum of Practical Geology, No. 8278. Bight valve. 

 10. Same museum, No. 8445. Portion of right valve x 4. 



11_13. P. (Neithea) Morrisi (Pict, and Renev.). (P. 201.) 



11. Hythe Beds, Lympne. Museum of Practical Geology, No. 8364. a, right 



valve ; b, posterior view of the same ; c, portion between two main ribs X 3. 



12. Same locality, etc., No. 8446. a, left valve ; b, posterior view of the same. 



13. PerHo-bed, Atherfield. Woodwardian Museum. Left valve — posterior margin 



restored. 



14—17. P. (Neithea) quinquecostatus, Sow. (P. 202.) 



14. Upper Greensand, Ventnor. York Museum, a, right valve ; b, anterior view 



of the same. 



15. Upper Greensand (zone of Pecten asper), Shaftesbury. Bristol Museum. 



a, right valve ; b, left valve ; c, anterior view. 



16. Same horizon, Warminster. Museum of Practical Geology, No. 8419. a, right 



valve; b, anterior view of the same. 



17. Upper Chalk (? M. cor-anguinum zone), Gravesend. Museum of Practical 



Geology, No. 8362. a, right valve ; b, left valve ; c, posterior view of the 

 same specimen. 



