18 CONTRIBUTIONS TO CANADIAN PALEONTOLOGY. 



Patula ANOULIPERA. (X. Sp.) 

 Plate t, figs. C, 6 a, and 6 b. 



Shell sublenticular, deeply umbilicated, periphery thin, angular and 

 rather distinctly keeled : upper side very gently convex or very obtusely 

 conical, nearly flat, the spire being raised only a little above the outer 

 "whorl. Volutions four, the firbt and second rounded above, the third 

 and fourth flattened >omewhat obliquely; lower side rather more con- 

 vex than the upper, narrowing oblirjucly and somewhat convexly to the 

 umbilical margin : umbilicus about one-third of the entire diameter of 

 the base, deep, conical and obtusely subangular at its margin. Aper- 

 ture trapezoidal, widest at a right angle to the axis of the shell, the- 

 columellar side being nearly parallel with the lower half of the outer 

 lip, which latter is thin and simple. 



Surface marked with minute and closely arranged stria?, which cross 

 the whorls transversely, and which are arched forwards on the upper 

 surface. 



3Iaximum breadth of the only specimen collected, sixteen millime- 

 tres : height or depth of the same, as measured from the apex to 

 the umbilical margin, eight mm. 



Pincher Creek, T. C. Weston, 1883 ; St. ilary E. Series : a nearly 

 perfect and tolerably well-preserved specimen. 



This angulated and keeled shell seerns to bear .somewhat the same 

 relations to the ordinary species with a rounded periphery that the 

 recent Patula Cumherlandiana of Lea does to P. alternata. 



PaTULA OBTrsATA. (X. Sp.) 

 Plate 2, figs. 7, 7a and 7b. 



Shell depressed, subdiscoidal, very moderately convex both above and 

 below, the height being less than one half the gi-eatest breadth : spire 

 obtuse, nearly flat and raised but little above the highest level of the 

 outer whorl. Volutions four to five, rounded, slender, and rather closely 

 embracing, so that the upper surfaces only of those of the spire are 

 exposed to view, except perhaps in the umbilical cavity : suture distinct 

 but not very deep ; outer whorl narrowly rounded at the periphery, 

 moderately convex and retreating obliquely to the umbilical margin 

 below : umbilicus about one-third the diameter of the base, deep and 

 with steep sides, but with a rounded margin. Aperture (as seen in the 

 few specimens collected, which may not be adult shells) apparently 



