104 EEV. E. BOOG WATSON ON THE 



St. Thomas, N. of Culebra Island, Danish "West Indies. 390 fms. 

 Mud. 



Shell. — Small, narrow, conical, with a blunt inflated apex, solid, 

 opaque, glossy. Sculpture. Longitudinals — there are on the last 

 whorl 16 rows of small rounded but not blunt tubercles, which 

 more or less continuously run obliquely down the spire in lines 

 from right to left ; the hollows which part them are in form 

 much like themselves ; there are also faint microscopic scratches 

 on the lines of growth. Spirals — on each whorl the tubercles are 

 arranged in two spiral rows, in which the tubercles have their 

 sharp tips tilted up the spire, and they are parted by a triangular- 

 shaped furrow, narrower than the spirals of tubercles. Below 

 the under row of tubercles is a broader furrow, in the bottom of 

 which runs the suture on the spireward face of a fine rounded 

 thread occupying the extreme upper edge of the subjacent whorl. 

 This thread is undulated rather than tubercled where it crosses the 

 longitudinal rows ; on the spireward side this thread is defined by 

 a minute deep square-bottomed trench, while on the basal side 

 it lies close in to the foot of the upper spiral row of tubercles. 

 Bound the edge of the base is a slight sharp narrow keel, which 

 the succeeding whorl as it grows buries in the spiral thread 

 mentioned above. At - 004 from the edge, and there forming a 

 ledge, the whole centre of the base is slightly projected : with 

 this exception, the flat and scarcely conical base has no orna- 

 mentation beyond the radiating lines of growth and the micro- 

 scopic spirals, which, though visible on the rest of the shell, are, 

 as usual, more distinct on the base. Colour dull translucent 

 white. Spire high, narrow, and conical. Apex blunt and in- 

 flated. The two embryonic whorls are larger, but otherwise very 

 much like those of C. metula, Lov., being turban-shaped and pro- 

 jecting beyond the succeeding whorls ; they are glossy and quite 

 smooth but for some very faint microscopic longitudinal and 

 spiral lines. Whorls 13, of very gradual increase, flat on the 

 sides ; the base, too, is flat, and very little conical. Suture linear, 

 almost hidden by the overlap of the subjacent whorl. Mouth 

 very small and square, with a minute, round, very short canal in 

 front, whose edges are reverted all round. Outer lip broken. 

 Pillar very small, extremely short, straight, but reverted at the 

 point. Inner lip not fully formed. H. 0*2. B. 0'06. Penulti- 

 mate whorl 0-02. Mouth, length 0-028, breadth 0"025. 



This species, which in shape resembles T. suturalis, Ad. & Eve., 

 may be easily distinguished from that species by the absence of 



