CONCHOLOGY. 
in a canal which is more or less elongated : the 
outer lip not changing its form by age. 
83. Pleurotoma, Shell turreted or  spindle- 
shaped, with a straight canal; outer lip cloven or 
notched at the upper end, Pillar smooth. 
Includes Murex gracilis. 
84, Fusus, Shell spindie-shaped without varices, 
with the spire elongated : outer-lip entire, smooth ; 
pillar smooth or striate externally. 
Includes Murex corneus and others. 
$5. Murex. Shell oval-oblong, furnished 
externally with rough varices which are three or 
more in number, and forming longitudinal con- 
tmuous rows. Aperture round. 
* Includes Murex Erinaceus. 
86. Tritonia. Shell oval-oblong, furnished with 
varices which are either alternate or solitary, and 
never forming longitudinal continuous rows : 
aperture oblong. 
Includes Buccinum Macula and others. 
8. ALATE. 
Aperture ending in a canal at its base ; the outer 
lip becoming dilated by age, and changing its form. 
$7, Rostellaria, Shell turreted or spindle-shaped : 
the outer-lip spreading as it advances to maturity, 
either entire or toothed or forming finger-like 
divisions ; aperture oblong, extending into a canal 
at the upper part. 
Includes Strombus Pes Pelecani, 
