APORRIIAIS. 187 



surface is decidedly lustrous, and tlie throat has frequently 

 a livid tinge. In addition to the fine sjiiral slightly raised 

 lines which closely traverse the entire exterior, the whorls 

 of the spire are adorned with longitudinal prominences, 

 which on the earlier rounded coils take the shape of close- 

 set obliquely arcuated narrow folds, and gradually as the 

 turns become angulated in the middle become converted 

 into a spiral row of rather small and moderately distant 

 laterally compressed subcentral nodules. Besides this 

 series, which is continued upon the body-whorl, two more 

 rows encircle the latter in the shape of more or less nodu- 

 lous carinse, which being divergently produced to the extre- 

 mity of the outer lip, form the angulated medial crests of the 

 labial digitations. The third of these keels, which also is the 

 less strong and less nodulous, is approximate to the other ; 

 the second is rather more remote from the first, than that 

 is from the suture, and lies nearly half way between the 

 latter and the extreme end of the tail. The spire, which 

 is composed of eight or nine turns, which are divided from 

 each other by a fine sutural line, and are of moderate longi- 

 tudinal increase, is rather shorter than the body, and 

 apparently ends in a rather obtuse point (but we have never 

 met with a specimen where it was quite perfect). Of the 

 acutely lanceolate processes or digitations into which the 

 greatly expanded outer lip is divided, all of which are sim- 

 ple (not geniculated) and gradually are acuminated to very 

 fine points, the first, whose base is attached to the three 

 lower turns of the spire, runs up (in the adult) almost per- 

 pendicularly to nearly the height of the apex, and at times 

 beyond it ; the second, whose lateral projection is by far 

 the greatest, bends a little upwards ; the third and fourth 

 (which latter is often rudimentary or almost entirely want- 

 ing) lean slightly downwards ; the fifth or caudal process 



