148 ACT .1 



of teeth, all of the same form, consisting of a narrow basal-plate 

 and :i crescentic reflexion (pi. 49, fig. 1, 2, 3, A. tortmtili*). 



Distribution world wide. The genus as here restricted contains 

 Actieonid:' \\ith one undivided spiral columellar fold, and no teeth 

 upon the inner lip above that fold, the aperture being narrow above 

 and more than half the total length of the shell. Two subgenera, 

 or better, sections, may be recognized among the recent species; for 

 the fossil groups see Structural and Systematic Conchology, ii. p. 356. 



Section ACTION. 



Shell with a single columellar plait, which passes continuously 

 into the anterior margin of the peristome. 



Section RICTAXIS Dall. 



Shell like Actceon, but with a slight prominence or oblique trun- 

 cation at the base of the columella. 



Section ACTION Montf., 1810. 



A. MARI/E A. Adams. PI. 19, fig. 13. 



Shell ovate-cyclindrical, spire obtuse ; longitudinally substriate, 

 transversely lirate, the lirse with an impressed median groove, inter- 

 stices closely latticed ; dull white, ornamented with two transverse 

 ashy bands. Aperture oblong, columella uniplicate. (Ad.). 



Chiu<i NM/.S ( Mus. Cuming). 



A. marice AD., P. Z. S. 1854, p. 60. Tornatelkt nmri<i- K\i.. 

 Conch. Icon., xv, f. 22. 



In this species the whorls are ornamented with two spiral, trans- 

 verse ash-colored bands and tin- line are double, each being divided 

 in the middle by a fine transverse groove. (Ad.). 



A. 8iKi; M.I.II Reeve. PI. 19, figs. 18, 19. 



Shell ovately conical, transversely densely striated throughout ; 

 livid ruddy color, banded with white at the sutures. Columella one- 

 plaited. (Rve.). 



Jap' m Si.-bald). 



'/" Hi i \ i . I'. Z. S. 1842, p. 61 ; Conch. Icon, 

 xv, j.1.:;, til. 



