Shell, Shell and Sand, Imperial   Updated 3/31/2008
Imperial's Shell and Shell and Sand patterns are exactly the same except that the Shell and Sand has stippling between the shells as shown on the right. I suspect that when Imperial first released the Shell version it didn't sell well so they added the stippling to make the design more interesting. It's worth noting that some auctioneers may list either pattern as Shell, so check carefully.
Shell plates, 9 inches

Marigold, 575, 750 (both 2004), 275, 375 (both 2006)

Smoke, 500, 750 (both 2003), 650 (2004), 450 (2007)

Shell bowls, about 7-8 inches

Amethyst, 155 (1997)

Blue, 2,800 (2004)

Marigold, 15-25

Smoke, 203 (eBay 2005)

Shell and Sand plates, 9 inches

Aqua/teal, 75 (2006), 85 (2007)

Green, 200 (2003), 275 (2004), 75 (2006), 135 (2007)

Marigold, 1,400 (2001), 1,700 (2002), 800 (2003),
   950, 2,000 (both 2006)

Purple, 1,400, 1,900 (both 2004),
   850, 1,400, 1,900 (all 2004), 1,300 (2006),
   1,050 (2008)

Smoke, 1,000 (2004), 1,000 (2006), 1,300 (2007)

Shell and Sand bowls, 7-8 inches

Aqua, 50 (2001)

Green, 40 (2005), 40 (2006), 35, 75 (both 2007)

Green, in metal frame, 170 (2006)

Helios, 20 (2005)

Lavender, 325 (2004), 215 (2006)

Marigold, 145 (2003), 45, 115 (both 2004), 35 (2005),
   30, 75, 90 (all 2006), 20, 65 (both 2007)

Marigold, pumpkin, 350 (2003)

Purple, 250 (2004), 75, 115, 135, 235, 425 (all 2005),
   55, 105, 300, 305 (all 2006), 225 (2007), 300 (2008)

Smoke, 225 (2004)

Teal, 225 (2004)