Scotch Bonnet (also known as the Spotted Bonnet)
Phylum: Mollusca, Class: Gastropoda, Order: Littorinimorpha, Family: Cassidae, Genus: Semicassis, Species: Semicassis granulata · Cassidae (Helmet and Bonnet shells family) · Gastropod (marine snail/univalve), whole shell with a globose, spiraled shape.
Species
Semicassis granulata
Shell Type
Gastropod (marine snail/univalve), whole shell with a globose, spiraled shape.
Family
Cassidae (Helmet and Bonnet shells family)
Size
Approximately 2 to 2.5 inches (5 to 6.5 cm) in length based on hand scale, which is typical for an adult specimen (adult range: 1.5 to 4 inches).
Color & Pattern
Pale cream to off-white base color featuring spiral rows of distinctive square or rectangular brownish-orange to amber spots. The surface exhibits a glossy finish, likely lacquered or polished for display.
Rarity
Common to Uncommon depending on region; highly prized when found intact on beaches after major storms, particularly in North Carolina where it is the official state shell.
Habitat
Subtidal marine environment, typically found on sandy bottoms and mud flats at depths ranging from 10 to 300 feet (3 to 90 meters).
Geographic Range
Western Atlantic Coast, ranging from North Carolina south through the Caribbean, Gulf of Mexico, and down to Uruguay.
Description
A well-formed, globose gastropod shell with a short spire and prominent body whorl. The exterior features well-defined spiral ribs intersected by faint axial growth lines, giving it a light grid-like texture. Decorated with regular horizontal rows of square amber-orange blotches.
Key Features
Rounded bonnet shape, short spire, strong spiral grooving/cords, and neatly arranged rows of square or rectangular yellow-brown to orange spots on a whitish background.
Collector Value
Low to Moderate ($5 to $15 USD for retail commercial specimens). Naturally beach-collected specimens in pristine condition hold significant sentimental value for collectors.
Condition Notes
Extremely Good to Fine condition with fully intact lip structure and sharp pattern markings. The high gloss indicates it may have been cleaned and coated or polished for retail sale.
Interesting Facts
The Scotch Bonnet was named the official state shell of North Carolina in 1965, making North Carolina the first U.S. state to designate an official state shell. These predatory snails feed primarily on sea urchins and sand dollars using specialized acid secretion and radula teeth to drill into their prey.
Ecological Role
Active benthic predator that controls populations of echinoderms like sea urchins (e.g., heart urchins) and sand dollars in soft-bottom marine habitats.
Similar Species
Mediterranean Bonnet (Semicassis saburon) which has finer spots and ridges, and the Mediterranean Helmet (Cassis tuberosa) which is much larger with triangular knobs.
Beach Finding Tips
Best found after severe ocean storms, tropical storms, or winter nor'easters along sandy beaches, particularly along the Outer Banks of North Carolina and Florida's barrier islands at low tide.