1) Family patellidae 2) Marine limpets 3) Mollusk family 
Patellidae is a taxonomic family of sea snails or true limpets, marine gastropod molluscs in the clade Patellogastropoda. Patellidae is the only family in the superfamily Patelloidea. This family has no subfamilies. (The superfamily Patelloidea should not be confused with the similar-sounding genus of true limpets Patelloida which is in the family...
(from the article `gastropod`) ...areas.Superfamily Patellacea (Docoglossa)Conical-shelled limpets, without slits or holes, found in rocky shallow waters (Acmaeidae and ...
[n] - marine limpets
family Patellidae noun marine limpets