225 



a little below ; a narrowly rounded band on the edge ; above which, con- 

 cave or nearly fiat to within one-fifth of the suture, where there is an 

 obscure thread-like carina ; then nearly horizontally bevelled into the 

 suture. The whorls are turretted about one-fourth their width above 

 each other. The body whorl just below the margin has a slightly concave 

 band ; below which, strongly convex. Aperture rhomboidal ; the upper 

 half of the inner side formed by the penultimate whorl ; the lower half by 

 a thickened effuse lip. The umbilicus is closed. Surface with rather 

 strong backward curving striae. 



Length 9 lines ; width 8 lines. 



This species is exactly like M. Bryope (see p. 170), but has the spire 

 more elevated. 



Varieties. — Associated with P. selecta are specimens with the spire not 

 quite so much elevated ; apical angle 85° ; the band on the margin nar- 

 rower ; the upper edge of each whorl having the plane of the bevel into 

 the suture more oblique, or sloping upwards instead of nearly horizontal. 

 The whorls are also less distinctly turretted. 



Locality and Formation. — H, I, K, L, Table Head, Newfoundland ; 

 Quebec group. 



Collector. — J. Richardson. 



Pleukotomaria vieguncula. (N. sp.) 



Pig. 209. 



Description. — Shell small with an evenly pyramidal spire ; apical angle 

 between 80° and 95° ; whorls four ; base convex. The body whorl has 

 a double band along the middle, consisting of two concave grooves and 

 three sharp narrow carinas, the one separating the two grooves bemg the 

 most prominent and constituting the margin. Above the double band is 

 another, rather strongly concave, and from one-third to half the width of 

 the upper side of the whorl. The upper side of this latter band is limited 

 by a fourth carina, above which the edge of the whorl is bevelled into 

 the suture. On the upper whorls only three of the carinae and two of 

 the grooves are visible, and the latter are there also usually of equal 

 width. The apex is acutely terminated. The base is rather strongly 

 convex. Aperture sub-rhomboidal, rounded on the inner side and angular 

 at the band. Inner lip greatly thickened. Umbilicus minute, and in 

 some specimens closed by the callous of the lip. Surface with fine striae. 



Length from 4 to 8 lines ; width a little less than the length. 



Locality and Formation. — H, I, K, L, Table Head, Newfoundland ; 

 Quebec group. 



Collector. — J. Richardson. 



