Southwest Florida Shells
by José H. Leal
Family Pseudomelatomidae
Pilsbryspira monilis
(Bartsch & Rehder, 1939)
Atlantic Necklace Turrid
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.