﻿PLATE LXXV. 



Concavum-zone. 



Figs. 1, 2. — Sonninia costata, 8. Buckman. 



Fig. 1. — Outline of the front view of the specimen depicted in PI. LXXIV, 

 fig. 1. (Page 338.) 



Fig. 2. — Suture-line of the same specimen, showing broad-stemmed superior 

 lateral lobe. 



Figs. 3 — 5. — Sonninia parvicostata, 8. Buckman. 



Fig. 3. — Part of the side view of a typical adult. 1 Bradford Abbas. My 

 Collection. Natural size. (Page 339.) 



Fig. 4. — Outline of the front view of the same shell. 2 

 Fig. 5. — Suture-line from another specimen. 



Figs. 6 — 8. — Sonninia brevispinata, 8. Buckman. 



Fig. 6. — Side view of a presumably adult example, showing twisted umbilicus 

 due to reclining ribs. 5 Bradford Abbas. My Collection. Natural size. (Page 343.) 

 Fig. 7. — Front view, showing compressed whorls. 4 



Fig. 8. — Part of the suture-line of the same shell, showing superior lateral lobe. 5 



1 The ribs of the inner whorls not clear enough ; last inch of outside of outer whorl too incurved. 



2 Aperture too compressed ventrally. The slope of an inner margin often varies with age, so 

 that there may be discrepancy between drawing (of aperture) and general description — a fact to be 

 noted in this and other cases. 



3 Too little inclusion. Ribs of last part of whorl incorrect. No rounded bulges on inner margin. 

 * Ventral area between carina and aperture fictitious. 



5 Should have been drawn upright. 



