112 EEV. E. BOOG WATSON ON THE 



defined by an inferior minute spiral furrow. With the exception 

 of this and of very faint microscopic spirals and lines of growth, the 

 base is quite plain. Colour dead white. Spire high and narrow, 

 with slightly convex outlines ; the lowest tubercled spiral on each 

 whorl slightly projects beyond the top of the whorl which follows. 

 Apex blunt and smooth. Whorls 13, flat on the sides, narrowed 

 upwards, constricted at the bottom above the suture. Suture 

 minute, but well defined by the furrow and by the thread which 

 lies in the bottom of it above the suture. Mouth square. Outer 

 lip broken. Pillar short but rather narrow. Inner Up incom- 

 plete. H. 036. B. 0-095. Penultimate whorl 001. Mouth, 

 length 0-08, breadth 0*05. 



This, as regards its sculpture, also belongs to the C. retkulatum 

 group. 



12. Ceeithixjm (Bittittm) lttscent^, n. sp. 



St. 135. October 18, 1873. Nightingale Island, Tristao da 

 Cunha Islands. 100-150 fms. 



Shell.- — Small, narrow, conical, blunt, with straight outlines, 

 rounded but not contracted at the base, solid, translucent, glossy, 

 white. Sculpture. Longitudinals — there are 17-18 longitu- 

 dinal rows of coarse, flat, rounded tubercles, parted by fur- 

 rows narrow and shallow ; these lines run very straight up 

 the spire. Spirals — on all but the first three whorls there are 

 three equally-parted spiral threads, which rise into tubercles in 

 crossing the longitudinals ; of these three spirals the highest is 

 the smallest and least prominent. The first whorl is smooth and 

 glossy, with a few irregular wrinkles ; the second is regularly and 

 curvedly ribbed and furrowed longitudinally; on the third the 

 general sculpture of the shell begins, but the highest spiral is 

 absent, only its place is indicated by a broader infrasutural de- 

 pression. The base has round its margin a sharp-edged thread, 

 and close within this a very faint furrow. Colour translucent 

 glossy white. Spire is high, narrow, and has straight outlines. 

 The base of each whorl projects slightly beyond the top of that 

 which succeeds it, and the suture is sunk in a well-marked furrow. 

 Apex is abrupt and rounded, but the extreme point is obliquely 

 prominent. Whorls 9, flat on the sides, narrowed upwards, and 

 constricted at the bottom above the suture. Suture linear and 

 very minute, but well marked by the furrow which lies above it. 

 Mouth squarish. Outer lip incomplete. Pillar straight, short, 



