PLATE XVI. 



Fig. 



1. Astarte Vallisneriana, Xi??^. Gutta-percha cast of the right valve, natural size. 



The original is from Whitley. 



2. Astarte Tunstallensis, King. Right valve (twice the natural size) of a testiferous 



specimen. Tunstall Hill. 



3. AUerisma elegans, King. Right aspect of a cast (natural size) showing impres- 



sions of the anterior and posterior adductor muscles 

 {a and h) ; and sinus (c) in the pallial line. Humbleton 

 Hill. 



4. — — Umbonal aspect (natural size) of a cast. Humbleton Hill. 



Belonging to Mr. J. de C. Sowerby. 



5. — — Magnified view of an impression of the pimples on one of 



the valves. Whitley. 



6. Psa\nmobia (?) sub-papyracea, King. Cast of right valve, nearly twice the natural 



size. Humbleton Hill. 



7. Solemya biarmica, de Verneuil. Left valve (a little enlarged) of a testiferous speci- 



men. Humbleton Hill. 



8. Solemya Phillipsiana, King. Cast (a little enlarged) of left valve. Humbleton Hill. 



9. Chiton Loftusianus, King. Cephalic valve, a little enlarged ; testiferous. Tun- 



stall Hill. 



10. — — Caudal valve, a little enlarged ; testiferous. Tunstall Hill. 



11, 12, 13. — Intermediate valves, a little enlarged ; testiferous. Tun- 



stall Hill. 



14. — — Left aspect (twice the natural size) of an intermediate (tes- 



tiferous) valve, showing area [a), and granulated sculp- 

 turing. Tunstall Hill. 



15. Rissoa Leighi, Brown. Cast, four times the natural size. Red Marls, Collyhurst, 



Manchester. Mr. Binney's specimen. 



16. Turbo Permianus, King. Gutta-percha cast, nearly twice the natural size. Original 



from Silksworth. 



(There are slight indications of spiral ribs (which, I believe, are 

 purely accidental) on the fossil ; but they are too strongly re- 

 presented in the figure.) 



17. Rissoa Gibsoni, 5ro^(7;^. Cast, four times the natural size. Red Marls, Collyhurst, 



near Manchester. Mr. Bowerbank's specimen. 



(The longitudinal ribs copied by the engraver are, I believe, purely 

 accidental.) 



