Family Pseudomelatomidae

Shell size to 28 mm; shell turreted, with pointed spire. Whorls shouldered. Sculpture of about 20 axial ribs. Numerous spiral threads present, giving beaded aspect to ribs. Strong spiral cord below suture. Suture distinct. Color pale-yellow, light-brown, or chestnut-brown.

Size to 15 Shell elongate-turreted, brown with spiral sculpture of cream-white to yellow nodules, about 10-12 larger ones per whorl, with a secondary cord of smaller tubercles anterior to the larger nodules. This species is very similar to P. albocincta (C.B. Adams, 1845), differing by details of the spiral sculpture and numbers of cords, but this may not warrant the separation of these two species. Moderately uncommon on Sanibel. The shell in the main image was collected by Lois Dunnan in 1995 at Gulfside City Park on Sanibel. The central image shows a detail of the siphonal notch, or turrid notch, an indentation that accommodates the anal siphon, a fold of the animal tissue that directs waste water away from the animal. The supplementary image to the right is more typical of beach-collected, local material. It was collected by Susan J. Hewitt, also at Gulfside City Park, in December 2012.

Shell size to 10 mm; shell turreted, elongate. Spire acute, comprising about 2/3 of shell length. Sculpture characteristically with two spiral cords that intersect about 10-12 weak ribs. Aperture small and slender, with thickened outer lip. Color light to dark gray-brown. White nodules form at intersection of ribs and cords.

Shell size to 30 mm; shell turreted, with spire occupying about 2/3 of shell length. Sculpture of about nine ribs crossed by raised spiral cordlets. Anterior canal short. Color dark-brown. For many years this species was misidentified by modern authors as Zonulispira crocata (Reeve, 1845). The shell in the main image was collected on West Gulf Drive Beach, on Sanibel, by Susan J. Hewitt in December 2012.