354 Fossils of the Calciferous Sandrock. 



Pleurotomaria abrupta, (N. s.) 



Description. — Sub-lenticular, with abroad vertical band beneath 

 the outer edge ; whorls four or five, slender, sub-cylindrical, con- 

 vex above and below. At the upper outer angle of the whorl a 

 rather strong rounded ridge follows all round, and beneath it a 

 flat or slightly concave vertical band, which at the aperture is one 

 line wide in a specimen nine lines in width, below the band, the 

 whorl is regularly convex. The umbilicus is about one third the 

 width of the shell. Surface unknown. 



Differs from R. aperta and R. calcifera in the vertical outer 

 side of the body whorl. 



I have seen no perfect specimens of this species but such as we 

 have clearly indicate its distinctions. 



Locality and formation. — Mingan Islands, White Limestone. 



Collectors. — Sir W. E. Logan, J. Richardson. 



Pleurotomaria miser, (N. s.) 



Description. — This species is closely allied to R. abrupta but 

 differs therefrom in having the lower side of the body whorl 

 sharply augulated in the middle and also in the presence of an 

 obtuse carina about the middle of the upper suface of each volu- 

 tion. Judging from the form of the fragments of the whorls the 

 aperture must be sub-pentagonal. It is evidently a smaller species 

 than any of the others ; width of largest specimen seen, five lines. 



Locality and formation. — Mingan Islands, White Limestone. 



Collectors. — Sir W. E. Logan, J. Richardson. 



Pleurotomaria Laurentina, (N. s.) 



Description. — Lenticular, spire depressed, whorls five or six, 

 on their upper sides slightly convex, but with a shallow con- 

 cave band just within their outer margin. The lower side of 

 the body whorl is a little concave just beneath the margin, then 

 moderately convex to the umbilicus within which it is rather 

 narrowly rounded. The umbilicus is deep and one fourth the 

 whole width of the shell. The cast of the interior exhibits an 

 acutely rounded margin, which, owing to the concave band above, 

 appears to be turned a little upward, or to have a narrow ridge all 

 round on its upper side. The aperture is sub-rhomboidal, the 

 inner upper side slightly indented by the penultimate whorl. 

 Width of largest specimen two inches and one fourth, height not 



