~ CONCHOLOGY. 
very short spire: aperture very open, the disk 
perforated by a longitudinal row of holes, 
Includes Haliotis tuberculata. 
68. Stomatia, Shell oval or oblong, somewhat 
ear-shaped, with a depressed nearly marginal spire. 
Aperture very open, with the lips united, without 
perforations along the margins, 
Includes Helix levigata, and A. Otis of Turton. 
69. Sigaretus. Shell roundish-oval, somewhat 
ear-shaped, with the spire depressed ; the inner-lip 
short and spirally involute. Aperture dilated, with- 
out perforations ; the lips disunited. 
Includes Helix haliotidea. 
ds. PLICACIDA. 
Aperture of the shell longitudinal, not expanded, 
entire at the base, and with a fissure at the back, 
Pillar furnished with plaits or teeth. 
70. Tornateila, Shelli cylindric-oval, trans- 
versely striate. Aperture narrow, oblong. Pillar 
with plaits at the base. Operculum horny, some- 
what kidney-shaped. 
Includes Voluta tornatilis. 
71. Auricula, Shell oval, quite smooth. Aper- 
ture oval-oblong. Pillar plaited at the base. 
Operculum none. 
Includes Voluta denticulata, and V. bidentata. 
72. Odontostoma, Sheil conic-oval, quite smooth. 
Aperture oval. Pillar with a single tooth or fold 
towards the middle, Operculum none. 
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