Shell of small to moderate size (usually 10-24 mm in length), conical to
elongate conical; smooth except for weak growth-lines and sometimes with
an angulation or keel at the periphery, rarely with microscopic spiral threads; aperture
without teeth; base usually perforated by a narrow umbilicus, which is hidden in aperture
view by middle portion of inner lip, which is folded back over it. Usually brownish in colour,
sometimes patterned with one or more spiral bands, some tropical species vividly coloured.

Most South African members of the Cerastidae belong to the genus Edouardia (Now: Gittenedouardia !!!), which was named (using French spelling) in honour of the eminent German malacologist Carl Eduard von Martens(1831-1904). Bark and porcelain snails are climbers, which during summer are found clinging to the trunk, branches or leaves of trees, sometimes as high as 7 m above ground, as well as on the leaves of low shrubs and bushes. However their urge to climb vertical surfaces also often leads to their ascending walls, fence-poles and other seemingly sterile vertical surfaces. In dry weather they aestivate under the bark of trees, or under dead leaves, rocks and logs. Some species are recorded as burying themselves under large rocks by day. A most intriguing report concerns the discovery of an aggregation of about 40 specimens of Gittenedouardia meridionalis on top of a sand dune, clinging to fish bones (observation by Olive Meyer) - perhaps making use of a ready supply of calcium or protein.
In life, the shell of most Gittenedouardia species bears a covering of what appears to be dust or, in the case of G. spadicea, bark particles. This provides very effective camouflage, the snails often being scarcely visible on the surface to which they are clinging. The origin of this covering needs investigation: although it may prove to consist merely of loose particles glued to the shell with mucus, it is difficult to conceive how the foot can apply such mucus even to the apical whorls of the spire! The body is drab, usually greyish or greyish-brown in colour, the optic tentacles very long, and the surface of the foot is usually minutely granular, with a weak keel along the upper mid-line of the tail. Bark snails presumably graze on microscopic algae and fungi growing on the bark or leaf surface. They have not been observed eating foliage of any sort.
In the genus Gittenedouardia the shell is rather fragile, often slightly translucent, and brownish in colour. Three groups of species are present in KwaZulu-Natal:

* GROUP 1 (G. spadicea, G. natalensis, G. carinifera) contains the broadest species (approximate ratio of length to width ranging from 1.05-1.24), usually with a peripheral keel, sometimes with a dark peripheral band, and an apex coloured like the rest of the shell.
* GROUP 2 (G. arenicola, G. meridionalis, G. dimera) are generally somewhat narrower (length: width ratio about 1.13-1.60), with a dark peripheral band (rarely a keel), and usually (but not always) with a dark apex.
*GROUP 3 (G. maritzburgensis, G. conulus, G. sordidula, G. metuloides) consists of the narrowest species (length:width ratio about 1.36-2.06), uniformly light brown without a peripheral ridge or band.


Most southern African species of Gittenedouardia are endemic to the region, but in addition to these the ranges of several East African species, belonging to the tropical genera Rhachis and Rachistia, also extend down the coastal corridor into northern Zululand. Members of these two genera have porcellaneous, more or less brightly patterned shells, which never bear a surface coating. In shell characters these genera are extremely similar to one another, and they differ mainly in characters of the radula. They are true tree snails, living on leaves and branches, often far above the ground. Some species in these genera, including Rachistia histrio from East Africa, have become widely distributed around the globe through accidental transport by humans.