466 CONTD^. 



adorned with an indistinct and irregular pallid zone near 

 the middle of the body-whorl. The surface is somewhat 

 nodosel}' decussated (at times almost cancellated) by the 

 abruptly prominent longitudinal ribs being surmounted by 

 acutely erect spiral lines. The former are not so broad as 

 their intervals, and are often a little aslant ; the latter are 

 more closely disposed than the costal (hence the lattices 

 are broader than long) and increase in number in propor- 

 tion to the frequency of the ribs ; in the littoral form there 

 are usually but five at most on the penult volution ; the 

 sculpture becomes granose on the rudimentary beak. The 

 whorls, whose longitudinal increase is gradual but not slow, 

 are profoundly and rather abruptly divided by a rather 

 slanting suture, gradually lessen to an extremely acute 

 apex, but do not taper much above ; they swell out with 

 some slitjht angularity beneath the suture, where a narrow 

 space (the seat of the successive emarginations) is com- 

 paratively free from sculpture, and are rounded or even 

 ventricose, though more conspicuously so in the large 

 variety (in which from the increased number of whorls 

 the spire is slightly longer than the fig-shaped body) than 

 in the smaller form, whei-e the converse for the most part 

 holds ffood. The basal declination is rounded, and the 

 anterior extremity is attenuated to a moderately narrow 

 but not elongated beak. The aperture, which fills about 

 three-eighths of the entire length, is of an oblong-elliptic 

 shape, being much contracted by an internal thickening of 

 the outer lip : it is contracted and produced below in a 

 sliortish but well marked canal, the commencement of 

 which is clearly indicated by the abrupt termination of the 

 much rounded simple arch of the outer lip. The throat, 

 which either partakes of the external colouring, or is of a 

 livid purple hue, is guarded at its entrance by numerous 



