PLATE XXX 



i. Egg and young of Stvophocheilus ovatus, Mull., natural size. 



2. Ianthina fragilis, Lamk., with its raft or float {a) ; and attachec 

 egg-capsules (b) ; c are the gills, and d the tentacles and eye-stalks. 



3. Egg-capsules of Common Whelk {Buccinum undatum, Linn.) : c, 

 inner side of a single capsule ; b, young shell, the natural size of which 

 is shown by the line near it. 



4. Nidamental ribbon of Jovunna Johnstoni, Aid. and Hanc, one 01 

 the Sea-slugs. 



5. Section of Fossil Oyster (Gryphcea arcuata, Lamk.), showing the very 

 numerous successive additions to the inner surface of the lower valve, 

 whilst the upper valve receives but few. 



6. Section of Spondylus varhiz, Lamk., the Water Spondylus, in 

 which spaces filled with sea- water are left between the successive layers 

 of the shell. 



7. Tn'gonU pcctinata, Lamk.: a. a'., adductor muscles; /., foot; Ji.L, 

 hinge ligament; I.t., labial tentacles; m., mantle margin: 0, mouth ; 

 p., pallial line ; tf , hinge teeth ; v., vent. 



S. Ensis siliqua, Linn., showing the powerful digging foot (/.) 



9. Isocardia hum ana, Linn. : /. , foot. 



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



