PLATE XVIf. 



Pleurotomaria arata. 



Pasre 61. 

 Fig. 1. The upjier side of the pplre of a very characteristic specimen, somewhat rompressed vert.inally, but 



not greatly distorted. 

 Pig. 2. The same, showing the depth of the volutions and form of the aperture. 

 Fig. 3. Ba«al view, showing the nmbilicus. 



Fig. 4. A cast, witli nmisnally elevated spire and rotund volutions. 

 Fig. 6. The summit of thf; same individual. 



Kg. 6. A vertically compressed specimen forming a 8ti*ong contrast with fig. 4. 

 Fig. 7. The upper surface of an obliquely compressed specimen which preserves the characteristic markings, 



and shows the spiral band with retrally cunning strife, as in tig. 1. 

 Fig. 8. An obliquely compressed sjtecimen with finer surface-markings. 



Pleurotomaria arata var. cxadsa. 



Page 65. 

 ^gs. 9, 10. Two views of a small gibbous specimen which bears a close resemblance to the more rotund 

 forms of P. arata. 



Pleurotomaria plena. 



Page 66. 

 Figs. 11-18. Three views of a large, well-formed specimen, showing the form, surface-markings and spiral 

 band. The outer volution is represented as slightly too rotund. 



