PLATE XVI. 



Concavum-beds. 

 Figs. 1 — 11. — Hyperlioceras Walkeri, S. Buchman. 



Fig. 1. — Side view of a very well-preserved type specimen, exhibiting the fine 

 lines of growth. Bradford Abbas, Dorset. Collected by my father. On account 

 of the strong recession of the inner margin the breadth of the whorl actually 

 decreases during the last half turn exhibited in the figure. (Page 92.) 



Fig. 2. — Front view of the same specimen, showing its compressed sides, and 

 the prominent carina characteristic of the genus. 



Fig. 3. — Side view of a smaller typical specimen, showing the period of change 

 from ribs to lines of growth only. Bradford Abbas, Dorset. Collected by my 

 father. 



Fig. 4. — Front view of the same specimen. 



Fig. 5. — Side view of a slightly more compressed specimen, with larger 

 umbilicus. Bradford Abbas. 



Fig. 6. — Front view of the same specimen. (Figs. 3 — 6 are to compare with 

 Plate XI, figs. 2—7.) 



Fig. 7. — Side view of a young specimen of this variety, showing the ribbing 

 and the commencement of the termination. Bradford Abbas. 



Fig. 8. — Back view of the same specimen. 



Fig. 9. — Side view of a smaller specimen, showing the gradual development 

 of the ribs from the almost straight single ones ; also a breakage in the she 

 which had healed over. 



Fig. 10. — Side view of a young specimen of a narrow-centred variety. Brad- 

 ford Abbas, Dorset. 



Fig. 11. — Front view of the same specimen. 



Figs. 12, 13. — Hyperlioceras discites {Waagen). 



Fig. 12. — Side view of a young specimen. Bradford Abbas. My Collection. 

 (Page 94.) 



Fig. 13. — Front view of the same specimen. 



