520 TROCHID^. 



As Da Costa wilfully changed the name of this shell, 

 even while he regarded it as the cinerarius of Linnaeus, we 

 adopt on reflection the name by which Montagu distin- 

 guished it ; since he clearly pointed out that it was not the 

 umhilicaris of Linnaeus, for which Pennant had taken it. 



A considerable degree of likeness exists between this 

 species and cinerarms, from which its colour, the broader 

 style of its painting, and the less numerous belts of its 

 base serve to distinguish it. 



It is a strong, opaque, and almost lustreless shell, of an 

 orbicular-conic form, convex lateral outlines, a small and 

 blunted apex, and a somewhat flattened base, that is 

 rounded-off" but yet subangulated at its edge. Upon a 

 ground of dull greenish white, or pale olivaceous yellow, 

 it is closely flexuously and rather obliquely streaked with 

 narrow stripes (not lines) of purplish red or reddish slate- 

 colour, which do not run parallel to each other, but diverge, 

 for the most part, further apart at the lower part of the 

 whorls, frequently become confluent above, and are often 

 interrupted, and occasionally somewhat reticulated, upon 

 the base. There are several simple raised spiral lines, that 

 for the most part are decidedly narrower than their inter- 

 stices, are sometimes prominent, yet at times so ill-defined 

 at their lower edges that the shell seems imbricato-sulcated ; 

 these are replaced at the basal margin by simple striae 

 (which are often obsolete), and are again renewed upon 

 the base, where the belts or sulci are by no means numer- 

 ous, and rarely much elevated. There are about five and 

 a half moderately increasing volutions, that are rather de- 

 pressed in proportion to their breadth, much shelving, and 

 rather more convex below than above ; the umbilicus is 

 profound, moderate in size, and margined with white. The 

 mouth is rather large, and decidedly broader than it is 



