Fig. 
1, 
3, 
5. 
“ID 
2 
Ne) 
PLATE XVII. 
2. Pleurotomaria antrina, Schlothem. 'Testiferous; natural size. Tunstall Hill. 
4. Pleurotomaria Tunstallensis, Avvg. Testiferous; natural size. Tunstall Hill. 
Magnified view of the apical whorls of a testiferous speci- 
men, showing spiral striz and sutural plications. Tun- 
stall Hill. 
Elongated variety, natural size; testiferous. Tunstall Hill. 
8. Pleurotomaria Linkiana, Azmg. Rather enlarged; testiferous. Humbleton Hill. 
. Pleurotomaria nodulosa, Azmg. Ai little enlarged ; testiferous: a, the slit. Tun- 
stall Hill. 
10, 11, 12. Euomphalus Permianus, Aizg. Thrice the natural size ; testiferous. Tun- 
13. 
14: 
to. 
stall Hall. 
Nautilus Frieislebeni, Geemitz. Cast (natural size) showing external face of the 
. Bairdia curta, A‘ Coy. 
outer whorl. Humbleton Hill. 
Lateral view of the last specimen: a, the siphonal sheath. 
Inner face of the outer whorl of the same: a, the siphonal 
sheath. 
Longitudinal section (enlarged) of a testiferous specimen, 
showing the siphonal sheath (az) passing through the 
septa. Humbleton Hill. 
. Nautilus Bowerbankianus, A7mg. Lateral aspect (natural size) of a _testiferous 
specimen. Tunstall Hill. 
Posterior aspect of the last specimen. 
Anterior aspect of the same. 
Nucleal whorls (twice the natural size) showing a septum 
perforated by the siphonal sheath (z). Tunstall Hill. 
Cast; magnified nme times. Dorsal aspect ; valves united. 
Humbleton Hill. 
Lateral aspect of the same specimen; right valve upwards. 
