169 



PLEUROTOMARIA ? VIOLA. (N. sp.) 



Description. A cast of the interior consisting of five whorls is twenty 

 three lines wide at the base and eighteen lines in height ; umbilicus nine 

 lines wide., and on inside exhibiting all the whorls quite to the apex. 

 The whorls are sub-cylindrical, gradually increasing in size ; transverse 

 section showing the form of the aperture elliptical, the width about one 

 fourth greater than the height. Width of the aperture about eight lines ; 

 height six lines. 



It is difficult to say whether this fossil should be called a Pleurotomaria 

 or a Murchisonia. The cast resembles a short Murchisonia with slender 

 cylindrical whorls and a very wide umbilicus. On the outer side there is 

 some appearance of an angulation, as if there were a band on the margin 

 of the shell. 



Locality and Formation. Gait ; in the Guelph formation. 

 Collector. E. Billings. 



PLEUROTOMARIA VALERIA. (N. sp.) 



Description. Large, conical ; whorls five or six, very gradually in- 

 creasing in size, with a sharp-edged margin all round. On the upper side, 

 as nearly as can be ascertained from the cast, the whorls have an obtusely 

 rounded angulation at about one third their width from the outer edge ; 

 above this angulation they are flat or gently concave to the suture ; below 

 it, also flat, and descending with an abrupt slope to the outer edge. The 

 latter presents a sharp angle of about 90. Just below it a gently con- 

 cave band about one and a-half lines wide. The remainder of the under 

 side of the whorls is gently convex, uniformly rounded into the umbilicus. 

 The aperture, as shown in the cast, is transversely ovate, depressed con- 

 vex above and below, narrowly rounded on the inside and angular on 

 the outside. Umbilicus about one half the whole width. 



Width 28 lines ; height 15 lines ; width of umbilicus 14 lines ; width 

 of aperture 9 lines ; height of the same 6 lines. 



This shell somewhat resembles P. Mora, but differs in being angulated 

 on the upper side of the whorls. 



Locality and Formation. Gait; in the Guelph formation. 



Collector. E. Billings. 



