*Images in development
Tellinoidea
Ligament both external and internal, internal part on a well defined chondrophore
Ligament external, some juveniles with an internal portion but this not on a defined chondrophore
Trigonal to elongate oval shell with lateral teeth
Thin white shells with a posteriorly directed chondrophore, pallial sinus very deep extending beyond the midline = Abra
Robust, donaciform, coloured shells with a wide shallow chondrophore, pallial sinus not extending to beyond midline
Ervilia castanea
Outline subovate to elongate ovate (L>H)
Posterior distinctly acute compared to rounded anterior
Posterior narrower than anterior but not acute
Ovate to subovate beaks just behind the midline or close to midline
Posterior dorsal area not depressed, dorsal margins finely denticulate (abyssal)
Abra profundorum
Shell with commarginal lines and growth stops (shelf)
Abra alba
Shell with commarginal lines and faint radial striations (continental margin & upper slope)
Abra longicallus
Elongate oblong shells gaping a both ends = Solecurtidae
Subovate to narrowly subovate, not gaping
Sculpture of commarginal lines and growth stops only, ventral margin slightly concave
Azorinus chamasolen
Sculpture of oblique riblets over commarginal lines and undulations
Narrowly subovate shells with a crenulate or serrate inner margin = Donacidae
Inner margin weakly denticulate, external with commarginal lines only
Donax variegata
Hinge with cardinal and lateral teeth
Hinge lacking lateral teeth
Subovate, with prominent commarginal ridges and weaker radial riblets
Tellina serrata
Subcircular to narrowly subovate shells with commarginal sculpture only
Sculpture of smooth commarginal ridges, pallial sinus developed equally in both valves
Arcopagia crassa
Sculpture of thin widely spaced commarginal raised threads, pallial sinus in RV half the depth of that in LV
Arcopella balaustina
RV anterior lateral prominent close to the beaks, posterior lateral indistinct
RV anterior and posterior laterals prominent
Valves lacking oblique microsculpture
Posterior subrostrate, kinked, pallial sinus separated from anterior adductor scar by width of anterior adductor scar
Tellina incarnata
Posterior subacute, not kinked, pallial sinus almost touching anterior adductor scar
Tellina tenuis
Beaks very close to posterior, posterior bluntly rounded, secondary internal ligament may persist in adult. Mostly uniform
Tellina pygmaea
Beaks close to the posterior posterior subacute, often colour rayed
Tellina donacina
Subovate to trigonal shells posterior shorter or narrower than anterior
Elongate oval to oblong shells length twice or more than height, anterior and posterior roughly equal in extent or curvature
Subovate, posterior subacute extended in adults, sculpture of commarginal raised ridges and delicate radial striations
Gastrana fragilis
Subovate to trigonal, posterior subacute to subtruncate, commarginal sculpture only
Shells broadly subovate, posterior subacute, pallial sinus confluent with pallial line, pallial sinus same size in each valve
Macoma balthica
Shells subovate to roundly subovate, pallial sinus partly confluent with pallial line, pallial sinus discrepant. [Subarctis /Arctic)
Shell oval, posterior slope short. posterior broadly rounded
Macoma loveni
Shell subovate, posterior slope long, posterior distinctly narrower than anterior
Posterior margin obliquely truncate, posterior area set off by sharp ridge
Gari fervensis
Posterior margin rounded to bluntly rounded
Posterior area with prominent radial riblets, remainder commarginal only
Gari costulata
Posterior lacking radial riblets
Anterior and posterior dorsal margins sloping, posterior and and anterior equally rounded
Gari tellinella
Posterior dorsal margin almost straight, posterior margin more broadly rounded than anterior
Gari depressa
