﻿PLATE LIX. 



Concavum-zone. 

 Figs. 1 — 3. — Sonninta aoanthod es, 8. Buckman. 



Fig. 1. — Back view of specimen depicted in PI. LVIII, showing the large 

 ribs, and the slight sulcus on each side of the carina. Natural size. (Page 319.) 



Fig. 2. — Side view of a young example. (The spines should be more promi- 

 nent in the last part of the whorl.) Bradford Abbas, Dorset. My Collection. 



Fig. 3. — Front view of the same specimen. The letter c marks the infilling 

 of the hollow carina, the letter b the hollow carina complete. 



