Wollaston’s Saint Helena Discus Snail (Helenodiscus vernoni)
Wollaston’s Saint Helena Discus Snail was described in the year 1892 on the basis of subfossil shells, which were found at the so called Side Path, a steep mountain pass, that connects the two villages of Briars Village and Jamestown in the north east part of the island of Saint Helena.
The shells of this species reached an average size of about 1,2 cm.
The species died out sometimes after the beginning of the permanent European settlement of the island in the 16.th century.
Saint Helena Diskus Snail (Helenodiscus bilamellata)
The Saint Helena Diskus Snail was described on the basis of subfossil shells, that were found on the island of Saint Helena, these shells were found among the remains of several other snail species, all of which are now extinct.
The shells of this species reached an average size of 0,8 cm in diameter.