Scotch Bonnet
Phylum: Mollusca, Class: Gastropoda, Order: Littorinimorpha, Family: Cassidae, Genus: Semicassis, Species: Semicassis granulata · Cassidae (Helmet and Bonnet shells) · Gastropod; whole shell, globose/ovate spiral shape
Species
Semicassis granulata
Shell Type
Gastropod; whole shell, globose/ovate spiral shape
Family
Cassidae (Helmet and Bonnet shells)
Size
Approximately 1.5 - 2 inches in length. This is a common mid-range size; adults typically reach 1.5 to 4 inches.
Color & Pattern
Pale cream to light tan base with a pattern of orange-brown square spots arranged in spiral rows. The pattern on this specimen appears slightly faded or sun-bleached. The outer lip shows characteristic dark brown spots along the edge.
Rarity
Common (frequently found beachcombing in Florida and the Caribbean), though pristine specimens with bright coloring are more sought after.
Habitat
Found in shallow to moderately deep tropical and subtropical waters, typically on sandy bottoms or seagrass beds where they can bury themselves.
Geographic Range
Western Atlantic, ranging from North Carolina and the Gulf of Mexico down to Brazil, including the Caribbean.
Description
A classic globose shell with a short spire and a large body whorl. The surface is decorated with numerous fine spiral grooves (granulations) and axial growth lines, giving it a plaid-like texture. The outer lip is thickened and reflected, often featuring small teeth (denticles) on the inner edge and dark spotting on the outer edge.
Key Features
Square brownish spots arranged in rows, a thickened and spotted outer lip, fine beaded or granulated surface texture, and a relatively short, pointed spire.
Collector Value
Low to Moderate ($3-$15). It is a popular starter shell for collectors. Larger specimens or those with exceptionally vibrant 'plaids' hold higher value.
Condition Notes
Good condition. The shell appears intact with no major breaks or predation holes. The colors are somewhat muted, suggesting it may have spent some time on the beach exposed to sunlight. Collectibility grade: Fine.
Interesting Facts
The Scotch Bonnet is the official state shell of North Carolina (the first state to designate one). These snails are predators that specialized in eating sand dollars and sea urchins.
Ecological Role
An active carnivore that helps regulate populations of echinoderms like sand dollars. They use a specialized proboscis to drill into the shells of their prey.
Similar Species
The Gulf Coast Toad-shell (Bursa granularis) has a more flattened shape and different nodules. The Mediterranean Bonnet (Semicassis saburon) is similar but has a different geographic range and finer markings.
Beach Finding Tips
Look along the wrack line after a storm or during extreme low tides on sandy Atlantic or Gulf beaches. They are often found partially buried in the sand near the water's edge.