Boonea bisuturalis
Boonea bisuturalis (also known as the three-toothed odostome or the two-groove odostome) is a species of minute sea snail, a pyramidellid gastropod mollusk or micromollusk in the family Pyramidellidae, the pyrams and their allies. The species is one of eleven known species within the Boonea genus of gastropods. This species is ectoparasitic (an external parasite) on various bivalves and other gastropods. It is notorious as a pest on oyster beds. Its preferred hosts are the common periwinkle "Littorina littorea", the mud snail "Tritia obsoleta" and the eastern oyster "Crassostrea virginica" Description. The length of the shell  varies between 2.8 mm and 5.8 mm. The smooth shell has a light brownish epidermis. The 5-6 whorls of the teleoconch show an impressed revolving line below the suture. The periphery is obtusely angulated. Distribution. This marine species occurs off Gulf of St Lawrence, Canada, and can exceed distribution throughout marine areas ranging from Canada to the state of Delaware, USA. The species is also notable within the Gulf of Maine.