False Rosy Strigilla
Strigilla pseudocarnaria (Boss, 1969)
Strigilla, family of Tellininae
The False Rosy Strigilla are fairly rare on S. Hutchinson Island. I have found a number of complete shells (both valves). They also resemble somewhat the Rose Tellin, to which they are related.
False Rosy Strigilla (S. Hutchinson Island- December, 2020)
Harry Lee: "These are Strigilla pseudocarnaria Boss, 1969: <Molluscabase - Strigilla pseudocarnaria Boss, 1969>. Vernacular name is the False Rosy Strigilla
This is an interesting occurrence, first noticed by Don Swenson, to wit <http://jaxshells.org/hobes.htm>. At the time of its description, this species was not known from continental North America, let alone FL. Swenson's work has turned up a number of such unexpected species of marine shells, and the smart money is on recent invasion from warmer climes (vs. historical oversight) since most of these taxa are not inconspicuous. Furthermore SE FL has been well-searched for shells since the Flagler Railroad opened it up to vacationers & settlers.
Its occurrence in SE FL is a bit spotty. Note its absence from Coral Cove <http://jaxshells.org/coralcove.htm>, Peanut Island <http://jaxshells.org/peanut.htm>, and Biscayne Bay <http://jaxshells.org/biscayne.htm>. Abbott (1974), Malacolog 4.01 (2009 <http://www.malacolog.org/search.php?nameid=13120>), and Huber et al. (2015) confine the taxon to true Caribbean waters."
The images below (3 and4) are the very similar Strigilla carnaria (Rosy Strigilla) forwarded to me by Harry Lee. Images 1 and 2 are False Rosy Strigilla.