CONCHOLOGY. 
63. Haminea, Shell thin, somewhat globular, 
without spire: aperture ‘narrow, as long as the 
shell. 
Includes Bulla Hydatis. 
64. Ovula, Shell oval involute, gibbous in ‘the 
‘middle, without spire: aperture much produced 
at the extremities. 
Includes Bulla patula. 
3. NERITIDZ. 
Shell somewhat globular or semioval: the left 
side of the aperture generally half-parted trans- 
versely. 
65. Natica, Shell umbilicate underneath, Aper- 
‘ture half-round; the imner-lip oblique; without 
teeth: the outer-lip acute. Operculum horny 
or testaceous. 
Includes the Marine Nerite. 
66. Lanthina. Shell somewhat globular, very 
fragile; aperture rather triangular; the pillar 
elongated, straight, and reflected ; operculum 
none. 
Includes Helix Ianthina. 
4, MACROSTAMOD#. 
Shell more or less ear-shaped, with a short 
Jateral spire-—Aperture very much extended. 
Pillar and operculum none. 
67, Haliotis. Shell -ear-shaped, broad, with a 
