Shell small to large, very inequilateral (beaks anteriorly placed), often irregular, gaping, with a single cardinal tooth in each valve. J. E. Gray introduced the family Hyatelladae, without description, in Parry & al.: Supplement to the appendix of Captain Parry’s first voyage, London 1824, p.ccxli “Shells”.
 

Shell small, transverse, irregular, gaping, byssate. sculpture made of commarginal growth marks. Pallial sinus deep.
 

« Shell transverse, gaping unevenly at both end. Hinge similar in one and in the other valve, having a callus or large elongated tooth placed in front and on the escutcheon; decurrent on the inner edge, raised in obtuse edge and projecting posteriorly; a slightly compressed and arched conical cardinal tooth [on the left valve], and on the right valve a dimple into which the tooth of the opposite valve engages; ligament external; beaks poorly protruding, escutcheon large, two muscular impressions in each valve located towards the ends. » – F. J. B. Ménard de la Groye: “Mémoire sur un nouveau genre de la famille des Solénoides”, Annales du Muséum d’Histoire naturelle de Paris vol.IX, Paris 1807, p.136.