PLATE IV. 



Fig. 



1. Pleurotomaria Campichei, Kpng., 1. a, enlarged y, Up ware. 



2. Pleurotomaria ferruginea, Kpng., Potton. 



3. Exogyra conica, Sby., Upware. 3. c, a striated variety (in Mr 



Walker's Collection). 



4. Ostrea Walkeri, Kpng., Upware. 



5. Neithea ornithopus, Kpng., Upware. 



6. Neithea atava (Rbmer), d'Orb., Upware (Coll. J. F. W.). 



