PLATE XVI. 
Fig. 
1. Astarte Vallisneriana, Azmg. 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. Allerisma elegans, Aimg. Right aspect of a cast (natural size) showing impres- 
sions of the anterior and posterior adductor muscles 
(a and 6); and sinus (c) in the pallial lime. Humbleton 
Hill. 
4. aa — Umbonal aspect (natural size) of a cast. Humbleton Hill. 
Belonging to Mr. J. de C. Sowerby. 
5. — =e Magnified view of an impression of the pimples on one of 
the valves. Whitley. 
6. Psammobia (?) sub-papyracea, Avmg. Cast of right valve, nearly twice the natural 
size. Humbleton Hill. 
7. Solemya biarmica, de Vernewl. Left valve (a little enlarged) of a testiferous speci- 
men. Humbleton Hill. 
8. Solemya Phillipsiana, Avg. Cast (a little enlarged) of left valve. Humbleton Hill. 
9. Chiton Loftusianus, Avzg. Cephalic valve, a little enlarged; testiferous. Tun- 
stall Hill. 
10. = aan Caudal valve, a little enlarged ; testiferous. Tunstall Hill. 
Weal2. NS: — 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, Collyharst, 
Manchester. Mr. Binney’s specimen. 
16. Turbo Permianus, A7mg. 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, Brown. 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.) 
