PLATE XXX— Continued. 
Pleurotomaria filitexta. 
Page 73. 
Fig. 15. The upper side of a small individual. 
Fig. 16. A large individual which is vertically compressed and somewhat distorted. 
Fig. 17. A large specimen, imperfect in the spire, which has been laterally compressed, giving an exag¬ 
gerated elevation to the volutions. These last two figures are from unusually large individuals 
of the,species. 
Pleurotomaria quadrilix. 
Page 86. 
Fi°\ 18. A lateral view, showing the form of the shell and the character of the peripheral band. The last 
volution is incomplete. Enlarged to 1 three diameters. 
Pleurotomaria nitella. 
Page 85. 
Fig. 19. A lateral view showing the form of the spire, the character of the peripheral band and stride (which 
are farther enlarged in fig. 4), enlarged two diameters. 
Pleurotomaria capillaria, var. rustica, n. var. 
Page 87. 
Fig. 20. The upper side of an imperfect spiecimen, showing the great expansion of the outer volution. 
Fi<r. 21. A lateral view of a similar form, which shows a much less elevation of the spire than the ordinary 
forms of the species. 
Fig. 22. A very large and much expanded specimen, which is apparently only an exaggerated form of this, 
variety. 
These all differ from the typical forms of P. capillana in the comparatively less elevated 
spire and greater expansion of the outer! volution. 
Pleurotomaria Lucina. 
Page 67. 
Fig. 23. The outer volution, showing the spiral band without defined limitation, and near the aperture the 
mark of a fracture during the life of the animal, followed by some irregularity in the subse¬ 
quent mode of growth. 
Pleurotomaria Lucina? 
See page 67. 
Fig. 24. A specimen of irregular form and growth, which has the aspect of a dwarfed and exaggerated 
variety of P. arata or P. Lucina, preserving some features of both. The striae, so far as preserved, 
have the character of the latter species, while the costae present much similarity to the former. 
Pleurotomaria Itys, var. tenuispira. 
Tage 87. 
Fig. 25. The posterior side of the specimen, showing the form of the aperture and rapidly attenuating spire, 
enlarged two diameters. See, also, figure 5. 
Pleurotomaria arata. 
Page 64. 
Fig - . 26. A very rotund form of this species. The specimen is a cast of the interior, preserving the remains 
of the concentric costae upon the upper side of the last volution. 
Fig. 27. The upper side of an extremely depressed specimen, partially preserving the shell in a macerated 
* condition, and showing the strong concentric costae. 
Murchisonia micula. 
Page 93. 
Fig. 28. An enlargement of the last volution, showing the peripheral band, with the impressed line below, 
and also the subcarinate feature of the upper margin of the volution. 
Murchisonia intercedens. 
Page 92. 
Fig. 29. The posterior side, showing the subcentral peripheral band and nearly entire aperture ; natural size. 
