PLATE XVII 



PELECYPODA: PROTOBRANCHIA 



i. Nucula Cobboldia. Sby. Fossil : Crag. 



2. Solenomya togata, Poli. 



3. Yoldia myalls, Couth. Fossil : Crag. 



PELECYPODA: FILIBRANCHIA 



4. Anomia A charts, Gray: p.p., scars of pedal and byssal muscles in 

 the left valve beneath, showing through the byssal opening in the 

 right valve above. 



5. Area zebra. Sby., showing byssal opening. 



6. Area Nocb, Linn. 



7. Limopsis aurita, Brocchi. Fossil : Crag. 



8. Glycimeris pectiniformis, Linn. 



9. Trigonia costata, Park. Fossil : Oolite. 



10. Mytilus smaragdinus, Chemn. 



11. Lithodomus lithophagns, Linn. 



12. Meleagrina margaritifera, Linn. (Pearl Oyster.) 



13. Ptevia hivundo, Linn. : b., byssal sinus. 



14. Spondylus princeps, Gmel. 



15. Hinnites sinuosus, Gmel. 



16. Malleus vulgaris, Lam. 



17. Pedum spondyloides, Gmel. : b., byssal notch. 



Other Filibranchs are shown on Plate XV., Fig. 8; Plate XVI., 

 Figs. 3A, c, and d ; Plate XXX., Figs. 6 and 7 ; Plate XXXII. , Figs. 13 

 and 17. 



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



