PLATE XV. 



Genus — Limopsis, Sasso. 

 Figs. 

 I — 4. L. albiensis, Woods. Gault, Folkestone. (P. 71.) 



1. Zone iii. Left valve. Museum of Practical Geology, a, outline ; 6, dorsal out- 



line ; c, exterior x 3 ; d, interior X 4. 



2. Zone vii. Eight valve x 4. Same museum. 



3. Eight valve x 3. Same museum. 



4. Zone ii. Part near umbo x 8. Same museum, 



5, 6. L., sp. Chalk Rock {Beussianum zone), Cuckhamsley. Montagu Smith 

 Collection, "Woodwardian Museum. (P. 72.) 



5. Cast of interior of right valve, a, outline ; h, dorsal outline ; c, same x 2 



6. Cast of interior of left valve, a, outline ; h, dorsal outline ; c, same x 2. 



Genus — Mytilus, Linnseus. 



7. M. inxquivalvis, Sow. G-reensand, Blackdown. The Type. Bristol 

 Museum, a, right valve ; b, left ; c, antero-ventral ; d, interior 

 of right valve near the umbo X 2. (P. 91.) 



Genus — Modiola, Lamarch. 



8 — 14. M, aequalis, Sow. Crackers, Atherfield. (P. 92.) 



8. Leckenby Collection, Woodwardian Museum, a, right valve, outline; b, same 



X 1^ ; c, dorsal of both valves. 



9. Wiltshire Collection, Woodwardian Museum. Eight valve. 

 10. Same Collection. Dorsal. 



11 — 13. Same Collection. 11, left valve; 12, right valve (slightly crushed dorso- 

 ventrally) ; 13, left valve 



14. Woodwardian Museum. Eight valve. 



15 — 18. M. reversa, Sow. Greensand, Blackdown. (P. 94.) 



15. Wiltshire Collection. Eight valve, young form. 



16. Wiltshire Collection. Left valve, young form. 



17. Wiltshire Collection, a, right valve ; h, dorsal outline of same. 



18. Woodwardian Museum, a, left valve ; h, dorsal of same ; c, portion just posterior 



to middle of the sulcus, showing radial ribs x 3. 



