MOLLUSCA. 
401 
Planaxis sulcata .— The Furrowed Plan axis. 
Plate LXXXV. fig. 16. 
Imperforate, transversely furrowed; grayish-white, and spotted 
with black, forming oblique longitudinal fasciae; outer lip 
internally crenulated and striated. One inch long. Inhabits 
the American seas. 
Genus 40. — TURBO.— Linnceus. 
Generic Character. — Shell conoid, or sub-turriculated ; aper¬ 
ture entire, round, margin of outer lip disunited; columella 
arcuated, depressed, but not truncated at the base; aperture 
provided with a testaceous operculum. 
Turbo setosus. — The Bristly Turbo. 
Plate LXXXV. fig. 17. 
Thick, transversely and deeply sulcated, and longitudinally 
striated; spire short; volutions rounded ; lip crenulated ; varie¬ 
gated with white, green, and brown; inside pearlaceous. Two 
inches long. Inhabits the Indian seas. 
Genus 41.—MONODONTA. — Lamarck. 
Generic Character. — Shell ovate or conoid; aperture round 
and entire ; outer lip disunited from the body at top ; columella 
arcuated and truncated at the base; aperture provided with an 
operculum. 
Monodonta coronaria .— The Thick-Lipped Monodonta. 
Plate LXXXV. fig. 10. 
Covered with numerous, small, scabrous, acute, tubercles; 
outer lip very thick ; apex blunt, white ; the columella reddish. 
One inch and a quarter long. Inhabits the Chinese seas. 
Genus 42.—TROCHUS. — Linnceus. 
Generic Character. — Shell conical; spire elevated, sometimes 
abbreviated; aperture transversely depressed; margin of outer 
lip disunited from the body at the upper part; columella 
arcuated, more or less oblique at the base; aperture provided 
with a horny operculum. 
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