PLATE LIV. 
HumpJiriesianum-zone. 
Figs. 1, 2. — DoESETENSiA OOMPLANATA, S. Buckwian. 
Fig. 1. — Side view of a slightly more involute variety, with fairly well-marked 
ribs becoming obsolete on the body-chamber. The letter a marks the solid 
carina. Frogden Quarry, Oborne. My Collection. (Page 306.) 
Fig. 2. — Suture-line of the same specimen. 
Figs. 3 — 5. — DoESETENSiA suBTECTA, 8. Buclcmafh. 
Fig. 3. — Side view of an immature form. The letter c marks the infilling of 
the hollow carina, e the place where the hollow carina terminated, as is shown by 
the disappearance of the partition-band (e is situated on the body-chamber, which 
began at X ) ; / shows the core of the carina without any partition-band — 
indicating that the body-chamber possessed an elevated carina into which the 
mantle penetrated, and which had not yet been shut off by a partition-band. 
(See page 81.) The suture-line is shown in situ. Frogden Quarry, Oborne. 
My Collection. (Page 309.) 
Fig. 4. — Side view of a fine specimen with the greater part of the test, and 
the elevated hollow carina preserved. Only the inner whorls possess small ribs. 
Frogden Quarry, Oborne. My Collection. 
Fig. 5, — Front view of the same specimen, (For the suture-line, see next 
plate.) 
(The specimens in this plate are arranged to show a gradually decreasing 
umbilicus correlating with loss of ribs. The solid carina has also been replaced 
by a hollow carina.) 
