PLATE LIII. 
Sumphriesianum-zone. 
Figs. 1 — 10. — DoESETENsiA coMPLANATA, S. BucJcman. 
Fig. 1. — Side view of a specimen without much test, but showing the mouth-border. One of the 
suture-lines is depicted in situ. Sherborne, Dorset. From my father's Collection. The letter a 
indicates the solid carina, which is, in places, rather too prominent. (Page 306.) 
Fig. 2. — Ventral area of the same specimen from above, to show the ventral lappet and the 
somewhat iniiated mouth. 
Fig. 3. — Side view of another specimen with more test preserved. (The body-chamber is nearly 
complete, and exhibits on each side o£ the carina a long spatulate depression — purposely drawn a little 
more distinct than it really is. It is suggested that these depressions indicate the place of attachment 
of the shell muscle.) Frogden Quarry, Oborne. My Collection. 
Fig. 4. — Back view of the same specimen, indicating the position of the depressions. The letter a 
in this and in fig. 3 marks a solid carina ; but towards the end of the body-chamber the carina is 
almost obsolete. 
Fig. 5. — Suture-line of the same specimen. 
Fig. 6. — Front view of a much compressed example, showing an extremely acute ventral area 
lacking the test. Frogden Quarry, Oborne, Dorset. My Collection. 
Fig. 7. — Suture-line of another example, showing inner lobes unusually retracted. 
Figs. 8, 8 a. — Two views of the inner whorls, magnified twice — the centre of the umbilicus is 
wanting ; 8 b, suture line. 
Fig. 9. — Side view of the inner whorls. The inner portion (to the break) is the same as shown in 
fig. 8, but is here drawn natural size. The part beyond the break is an extra half-whorl added. 
Fig. 9 l. — Front view ; 9 c, part of suture-line. 
Fig. 10. — Side view. This is the specimen which furnishes the inner whorls shown in figs. 8, 9, 
but now put back into their right position. The two outer whorls are added to the inner whorls 
depicted in fig. 9, and the whole then illustrates the time and manner o£ the acquirement of broad 
compressed whorls. Frogden Quarry, Oborne. My Collection. 
Fig. 10 a. — Outline of the whorls in section, showing the change in shape. 
Figs. 11 — 16. — DoESETENSiA LiosTEACA, S. BucTcman. 
Fig. 11. — Side view of a young example showing the obsolescence of the ribs. (The carina is solid 
at ff, but the piece on the top marked 5 is distinctly hollow.) Oborne. My Collection. (Page 310.) 
Fig. 12. — Suture-line. 
Fig. 13. — The first whorl of this species, side view ; 13 a, front view ; 13 l, 13 c, portion of the 
second whorl ; 13 d, 13 e, part of the third whorl, showing increase in suture-liue. (All the drawings 
of fig. 13 are considerably enlarged.) 
Fig. 14. — An outline of the section of the remaining whorls of the specimen which furnished the 
inner whorls, fig. 13. Natural size. (This outline shows the time when the compressed whorls 
commenced.) Oborne. My Collection. 
Fig. 15. — Side view of a young example with solid carina, showing early age at which the broad 
whorls began. (The costa? shown in the umbilicus are far too prominent.) Oborne. My Collection. 
Fig. 16. — Suture-line. (The superior lateral lobe is too wide and the saddle too shallow.) 
