PLATE XLVI. 
Goncavum-zone} 
Figs. 1 8. — DUMORTIEEIA GEAMMOOEEOIDES, Haug. 
Fig. 1. — Side view of a fine adult example with most of its test preserved. 
Bradford Abbas, Dorset. My Collection. (Page 262.) 
Fig. 2. — Front view of the same specimen ; the carina is perhaps rather too 
conspicuous. 
Fig. 3.^ — Part of the suture-line of the same specimen. 
Fig. 4. — Side view of the involute form ; nearly all its test is preserved. 
Bradford Abbas, Dorset. My Collection. 
Fig. 5. — Front view of the same specimen. 
Fig. 6. — Side view of an evolute form with more distant ribs. Bradford 
Abbas. From my father's Collection. 
Fig. 7. — Front view of the same example. 
Fig. 8. — Suture-line taken from another specimen. (The siphonal lobe should 
be shown more branched, and the inferior lateral lobe more perpendicular.) 
1 It has been thought advisable to call this horizon definitely " Concavum-zone." It is the same 
horizon which was described as " Sowerhi/i-zoue" or Sowerlyi-zone (Concavmi-heda) " until PI. XIV, 
and afterwards " Goncavum-heds.^' These terms may be altered to Concavum-zone. 
