Nucinellidae is a family of bivalves, in the order Solemyida. Its species are small and principally reside in deep-water environments. The species' average length is less than 5 millimetres (0.20 in), the largest species being Nucinella boucheti (La Perna, 2005) at a length of 25 millimetres (0.98 in). The family's characteristic features include large gills and reduced palps and their appendages; oval shells with few hinge teeth; they possess a single adductor muscle and one divided foot exhibiting papillae. The family contains two known genera: Huxleyia and Nucinella. Speaking of Nucinella, the genus' ligament system is of the simple arched type, lacking nymphae. Regarding the former, the system is "submerged" beneath its dorsal margin.

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