The Cystiscidae is a family of minute to small gastropods with shells that are usually smooth and white, occasionally coloured, with strong plaits on the columella. Most species of the family are less than six millimeters in length, although there are some larger, attractive tropical species.

The Marginellidae shares general shell appearance and features with the Cystiscidae but the two families have been distinguished.

The Cystiscidae was separated from the Marginellidae on shell and anatomical characters, and is considered to be more closely related to the Olividae, while the remaining Marginellidae have more in common with the Volutidae.

There are three major shell differences between the Cystiscidae and Marginellidae:

1) In the cystiscids the internal whorls of the shell are resorbed by the animal as the shell grows, leaving the shell interior hollowed out.

2) The columellar plaits differ in structure. In the marginellids, the plaits that are visible externally on the columella have been the same in number since the larval shell commenced growth. In the Cystiscidae only three or four of the plaits visible on the adult columella have been produced continuously as the shell grew, the remainder, the upper ones, only appearing in the last quarter or eight of a whorl. Those present since the juvenile shell are termed ‘plaits’, while the shorter upper ones are termed ‘lirae’. It is usually not possible from an external view of an adult shell to tell the difference, so descriptions give the total of plaits/lirae.

3) The Cystiscidae usually lack an external thickening of the outer lip, while this is usually present in the Marginellidae

Show sidebar
Persicula cingulata (Striped Marginella)
2 products

Persicula cingulata (Striped Marginella)

View products
Persicula persicula (Spotted marginella)
4 products

Persicula persicula (Spotted marginella)

View products