Scotch Bonnet (also known as the Banded Bonnet)
Phylum: Mollusca, Class: Gastropoda, Order: Littorinimorpha, Family: Cassidae, Genus: Semicassis, Species: Semicassis granulata · Cassidae (Helmet and Bonnet family) · Gastropod (univalve), whole shell with a spiral shape
Species
Semicassis granulata
Shell Type
Gastropod (univalve), whole shell with a spiral shape
Family
Cassidae (Helmet and Bonnet family)
Size
Approximately 2 to 3 inches in length, which is average for an adult specimen of this species. Full-grown adults typically range from 1.5 to 4 inches.
Color & Pattern
Glossy finish with a creamy-white base color overlaid with distinctive rows of square or rectangular golden-brown to orange-brown spots and blotches forming spiral bands. The colors appear fresh and natural.
Rarity
Common to Uncommon, frequently sought after by beachcombers in the southeastern United States and Caribbean.
Habitat
Inhabits shallow subtidal waters down to moderate depths, typically found on sandy bottoms, sand flats, and near coral reefs or seagrass beds.
Geographic Range
Western Atlantic Ocean, ranging from North Carolina through the Gulf of Mexico, the Caribbean Sea, and down to Brazil.
Description
An attractive, sturdy rounded shell featuring a short spire, inflated body whorl, and finely beaded spiral cords intersecting with subtle axial grooves. The outer lip is slightly thickened and subtly toothed, and the aperture is wide and clear.
Key Features
Rounded, inflated body whorl, low spire, distinct spiral rows of square brown spots, and finely beaded (granulated) sculpture across the surface.
Collector Value
Moderately popular among shell collectors due to its pleasing geometric pattern and glossy appearance. Common specimens have a modest value, though large, flawless specimens command higher interest.
Condition Notes
Gem to Fine condition. The shell is intact with vibrant natural coloration, clear spot patterns, a glossy finish, and no major structural damage, chipping, or extreme bleaching.
Interesting Facts
The Scotch Bonnet is the official state shell of North Carolina. The living snail feeds primarily on sea urchins and sand dollars, subduing them with a specialized acidic secretion to drill through their tests.
Ecological Role
Acts as a significant predator of benthic echinoderms like sea urchins, helping to control local populations. It also provides secondary housing for hermit crabs after death.
Similar Species
Other helmet and bonnet shells such as the Yellow Helmet (Cypraecassis testiculus), which is generally darker, lacks the distinct square spotting pattern, and has a more heavily toothed outer lip.
Beach Finding Tips
Best found by beachcombing on barrier island beaches after strong offshore storms or rough wave action, particularly along the coast of North Carolina, Florida, and the Gulf Coast.