241 



Description. — Shell about two inches across, consisting of four or five 

 slender whorls. Spire flat or very slightly convex in the middle, upper 

 side of the whorls with a concave band, occupying the outer half, the 

 inner half elevated, and either convex or with the most prominent part 

 slightly flattened. The margin is nearly acutely angular. The outer side 

 of the whorl, below the margin, is either flat or gently concave, and sloping 

 inwards at an angle of about 70°, with the plane of the spire in the body- 

 whorl, but from 60° to 70" in the smaller whorls. The umbilicus is about 

 five-sixths of the whole width, the edge rounded angular in the last whorl ; 

 acutely angular in the inner whorls. The slope of each whorl into the 

 umbilicus is gradual, and sometimes a little concave near the edge, then 

 convex, and lastly, nearly vertical. All the whorls are exposed to the 

 apex. The aperture is obscurely rectangular in the last whorl, but 

 more nearly oval in the inner whorl ; the Avidth a little greater than the 

 height. 



Surface with strong rugose transverse strise, and often with shallow 

 concave grooves, from two to three in two lines. 



The casts of the interior somewhat resemble those of M. transitionis, 

 but are distinguishable by the form of the upper side of the whorl, the 

 margin of which, instead of being uniformly rounded, as in the species 

 cited, is obliquely truncated by an obscure flat band, which slopes outwards 

 and downwards at an angle of 15" to 30" with the plane of the spire. The 

 acute edges of the margin of the shell and umbilicus are more obtuse or 

 obsolete in the cast. 



The last whorl is sometimes a little vagrant. 



A specimen 13 lines in width is 4 lines in height. 



Locality and Formation. — G, H, I, K, L, M, Point Rich, Table Head, 

 Cape Norman, Schooner Island in Pistolet Bay, entrance to the north arm 

 of Bonne Bay, Newfoundland ; Quebec group. 



Collector. — J. Richardson. 



Macltjrea tkansitionis. (N. sp.) 



Description. — Shell small, about two inches across, of about four 

 slender whorls. Spire flat; the suture in casts of the interior deeply 

 impressed ; the outer margin rounded ; the outer side of the last whorl 

 depressed convex and nearly vertical. The umbiUcus is nearly the whole 

 width of the shell, with an acute edge. The inner side of the whorls in 

 the umbilicus has two slopes. The first, commencing at the edge of the 

 umbilicus, extends about one-third the width of the whorl, inclined at an 

 angle of 45" or somewhat less, to the plane of the spire ; it is usually 



