Scotch Bonnet
Phylum: Mollusca, Class: Gastropoda, Order: Littorinimorpha, Family: Cassidae, Genus: Semicassis, Species: Semicassis granulata · Cassidae (Helmet shell family) · Gastropod, whole spiral shell
Species
Semicassis granulata
Shell Type
Gastropod, whole spiral shell
Family
Cassidae (Helmet shell family)
Size
Approximately 2.5 inches in length, which is average for this species. Adults typically range from 2 to 4 inches.
Color & Pattern
Cream to light yellowish-white base color adorned with distinctive rows of square or rectangular reddish-brown to orange-brown spots arranged in spiral bands. The finish is smooth with a glossy sheen in prime specimens.
Rarity
Common to Uncommon, highly prized by beachcombers though occasionally found washed ashore after storms.
Habitat
Shallow subtidal waters to moderate depths, typically found on sandy bottoms, sand bars, and offshore shell gravel beds.
Geographic Range
Western Atlantic Ocean, ranging from North Carolina through the Gulf of Mexico, the Caribbean, and down to Brazil.
Description
An elegant, oval-shaped marine snail shell featuring a short spire, inflated body whorl, and characteristic spiral sculpting. The outer surface is marked by distinct rows of square reddish-brown spots that resemble traditional Scottish tam o' shanter cap patterns, giving the shell its common name.
Key Features
Inflated body whorl, low spire, smooth to finely granulated spiral cords, and characteristic square reddish-brown markings arranged in neat rows.
Collector Value
Moderately high demand among regional collectors and casual beachcombers alike. Specimens with bright, unfaded colors and intact lips command higher prices, typically ranging from $5 to $20 depending on size and condition.
Condition Notes
Good overall condition with natural coloration largely intact, minimal fading, no major structural cracks or deep boring holes, grading as a Fine specimen.
Interesting Facts
The Scotch Bonnet is the official state seashell of North Carolina. The living snail is a specialized predator that feeds primarily on sea urchins and sand dollars, using its proboscis to bore through their tests.
Ecological Role
Acts as a primary predator of echinoderms like sand dollars and sea urchins, helping to regulate their populations in benthic marine communities.
Similar Species
Semicassis inflata and other helmet shells, which can be distinguished by differences in nodule prominence, overall shape, and specific spot arrangement.
Beach Finding Tips
Look along outer banks and high-energy beaches following major offshore storms or tropical systems, particularly during low tide on exposed sandbars.