Solen marginatus Pulteney, 1799
Norway & Baltic to Sénégal, Azores to Mediterranean & Black Sea. Burrows in sand or muddy sand, from intertidal to sublittoral. Filter feeder.
Synonyms: gladius, rotundatus, vagina auct.
Shallow water in sand, Grado, Friuli Venezia Giulia, NE. Italy. 104-107mm. L.D. Kellner legit (DE).
Solen marginatus in Forbes & Hanley: A history of British Mollusca and their shells vol. IV plate XV, London 1853, via BHL, with details of the siphons, vol. I plate I.
Notice the sculpture of the anterior adductor scar (left detail),
and the sand grains captured near the pallial sinus (right). Grado, 57-108mm.
Solen marginatus in L. A. Reeve: Conchologia iconica vol. XIX, London 1874, via BHL.
 
« The bordered Solen. Shell rather narrow, convex, fulvous ; epidermis thin ; dorsal margin straight, dorsal area linear, inconspicuous ; umbonal area broad, rather rough ; ventral margin very slightly excavated in the middle ; anterior margin oblique, raised, single-ribbed, constricted behind the rib by a deep canal. »
Inside of Solen vagina Pennant (non Linnaeus) in L. A. Reeve: Conchologia systematica vol. I, London 1841, via BHL.
Solen vagina in G. P. Deshayes: “Hist. nat. des mollusques”, Atlas, Exploration scientifique de l’Algérie, Paris 1844-1867. Obviously, this is a vagina Pennant; hence, a marginatus.
 
Figures 4 & 5: e = anal siphon, f = branchial siphon. Like in the Solecurtidae, these organs are composed of numerous segments that can be successively left in case of predator attacks. Figure 7 shows a front-view of such injured siphons, and fig. 6 displays a top-view of the same: notice the absence of the tentacles, gone with the final segment during an attack.

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