PLATE XX 



PELECYPODA : EULAMELLIBRANCHIA 



H. Adesmacea 



i Barnea Bakeri, Desh. : a, anterior adductor muscle scar ; a', 

 posterior adductor muscle scar. 



2. Martesia acuminata, Sby. 



3. Xylophaga dorsalis, Turton : a, dorsal view ; b, lateral view. 



4. Teredo Norvegica, Speng. : a, outer view of valve ; b, inner view of 

 valve. 



5. Teredo Norvegica, Speng. Siphonal end of the shelly lining to the 

 burrow, broken to show the septa. 



6. Xylotrya bipinnata, Turton. The pair of shelly styles that are 

 attached near the ends of the siphons in all members of tne genus, 



7. Teredinia personata, Lamk. Fossil: London Clay. Front view. 



8. Teredinia personata, Lamk. Fossil: London Clay. Side view, 

 with part of tube. Sa, Siphonal orifice. 



Another example of the Adesmacea is shown on Plate XXXII. , 

 Fig. 16. 



I. Anatinacea 



9. Thracia \ pubescens, Pult. 



10. Anatina subrostrata, Lamk. 



11. Pandora inizqnivalvis, Linn. 



12. PJioladomya Candida, Sby. 



13. Pholadomya Candida, Sby. 



14. Myochama anomioides, Stutch., left valve. 



15. Myochama anomioides, Stutch., right valve. 



16. Lyonsia Norvegica, Chemn. 



17. Chamostrea albida, Lamk. 



18. Chamostrea albida, Lamk. 



19. Brcchitcs vaginiferus, Lamk. 



PELECYPODA : SEPTIBRANCHIA 



20. Verticordia cardiiformis, Wood. Fossil : Cra< 



21. Poromya hyalina, Sby. 



22. Cuspidaria cuspidata, Olivi. 



23. Cuspidaria cuspidata, Olivi. 



*%* All Figs, from drawings by S. P. Woodward. 



