PLATE LV. 
Humphriesianum-zone . 
Figs. 1, 2. — DoESETENSiA suBTEOTA, S. Buchnan. 
Fig. 1. — Suture-line of the specimen depicted in PI. LIV, fig. 4. (Page 309.) 
Fig. 2. — Radial curve of tlie same specimen. 
Figs. 3 — 5. — DoESETENSiA LiosTRACA, 8. Buckmau. 
Fig. 3. — Side view of a fine adult example, showing on the cast the impression 
of the rim of part of the mouth-border. The letter e marks the place where 
the partition-band terminated ; and the letter / indicates the cast of the carina 
(page 81) without any partition-band. Oborne. My Collection. (Page 310 ) 
Fig. 4. — Side view of a young specimen. The letter b indicates the hollow 
carina. Oborne. My Collection. 
Fig. 5. — Side view of a variety showing a return to a costate stage. Oborne. 
My Collection. 
