﻿PLATE LXX. 



Concavum-zone. 

 Fig. 1. — Sonninia revikescens, 8. Buchman. 



Fig. 1. — Side view of a portion of a specimen showing the coarse distant ribs 

 of the last half -whorl, the preceding half- whorl being very obscurely ribbed. 

 (The outer whorl is without test.) Bradford Abbas, Dorset. My Collection. 

 (Page 324.) 



(This drawing is a copy of a photograph about one-half the natural size. 

 The fossil measures 238 mm. [9f inches] in diameter.) 



Figs. 2 — 4. — Sonninia simplex, 8. Buchman. 



Fig. 2. — Side view of example with test, showing the excentric umbilicus. 

 Bradford Abbas, Dorset. From my father's Collection. (Page 326.) 



Fig. 3. — Section of the whorl in outline, showing rounded ventral area of last 

 whorl and subcarinate area of preceding whorl. 



Fig. 4. — Suture-line from another specimen. Natural size. 



Fig. 5. — Sonninia modesta, 8. Buchman. 

 Fig. 5. — Suture-line of a typical specimen. (Page 325.) 



(This drawing is a copy of a photograph, and is within a fraction of natural 

 size. For side and front views of another specimen see PI. LXVIII.) 



Figs. 6, 7. — Sonninia substriata, 8. Buchman. 



Fig. 6. — Side view of a young specimen with test ; the inner whorls show no 

 spines. 1 Bradford Abbas. My Collection. (For adult see PI. LXXI.) (Page 330.) 

 Fig. 7. — Front view of the same fossil. (The aperture too narrow ventrally.) 



1 The ribs are too conspicuous, too irregular, and, towards the end, too much reclined. The 

 umbilicus is too large, the curve of the last quarter-turn of the inner margin being incorrect. 



