The shell is egg-shaped and fairly large, 2 to 4 inches (5 to 10 cm) in maximum dimension, with a regular pattern of yellow, orange or brown squarish spots.

This species lives intertidally and subtidally on sandy substrates, and is found primarily in the tropical and subtropical Western Atlantic Ocean, from North Carolina to Uruguay.

The eggs hatch as veliger larvae, which can float in the plankton for up to 14 weeks before settling onto the seabed as tiny snails.

Nearly a century after Born's description, in 1877, the Swedish naturalist Otto Andreas Lowson Mörch proposed a new combination and transferred this taxon to the genus Cassis and subgenus Semicassis.

The currently accepted combination, Semicassis granulata, was proposed by New Zealand paleontologist Alan Beu, based on paleontological data.

[20][21] There is a similar-looking species, Semicassis undulata, which lives in the Mediterranean Sea and the Macaronesian Islands, parts of the northeastern Atlantic.

It is also found in Bermuda, the Greater Antilles, Cuba, Jamaica and Puerto Rico, and further south in the Atlantic coast of South America, Suriname, Brazil (Amapá, Maranhão, Ceará, Rio Grande do Norte, Pernambuco, Alagoas, Bahia, Espírito Santo, Rio de Janeiro, São Paulo, Paraná and Santa Catarina), and also in Uruguay.

[12] In contrast, the species Semicassis undulata occurs in the Mediterranean Sea, and parts of the North Atlantic Ocean, including Portugal and the Azores.

[32] Several times at different growth stages, the shell develops a thick outer lip, which is characteristic of the subfamily Cassinae.

[16] In some cases, especially in deep water, the Scotch bonnet does not absorb the outer lip completely, leaving behind a varix on the whorls of the mature shell.

[32] The shell is colored pale tan or creamy white, sometimes purplish, with regularly-arranged, orange to light brown rectangular markings[34] that often appear faded, even in fresh specimens.

[34][36] Semicassis granulata lives on sandy substrate in moderately shallow water, as well as rocky tide pools close to the shore.

[12][27] These snails are often found in association with the offshore Atlantic calico scallop beds, probably attracted by the abundant food.

[16] During the spring, favorable food supplies, adequate light, and optimum water temperature provide conditions for breeding and early growth.

At this time, the female deposits hundreds of egg capsules in tower-shaped structures about 4 to 5 inches (10 to 13 cm) high.

As the veligers mature, they develop their first shell (the smooth protoconch) and turn into very small juvenile snails, at which point they sink to the ocean floor.

[38] On the coast of the Caraguatatuba, Brazil, a study of shell use in the diogenid hermit crab species Isocheles sawayai was carried out.

[37] Populations of S. granulata have been suffering a decline due to increased collection and accidental harvesting by commercial fishermen.