Several studies on Sri Lankan snails have been made over the years, but there is currently nothing that could be described as an identification guide. This guide provides images of shells, which provide the most straightforward method of identification. Simply compare your sample with the images, taking careful note of the different magnifications. Where examples from the type series were located, these have been figured, for the remainder the authors have relied on historical material held by the Natural History Museum, London (NHM) collections and loans from other institutions. A guide such as this is not the place for revisionary work, by the authors have made corrections to some original publication dates in their species list.
Shells are a record of all stages of growth; if you examine the early whorls on the adult shell they will give you an indication of what the juvenile looked like and you can make careful whorl-by-whorl comparisons. The tightness of gastropod coiling can be a useful character, but juvenile shells may have very different proportions to those of adults and may look very different. Due to space limitations only examples of adults are illustrated in this guide. The best thing is to build your own shell collection that includes the different growth stages of each species. This will allow you to recognize juveniles when you come across them. Small-scale collection of empty shells will not have harmful effects on populations, but it must be remembered that some species are endangered and living specimens of these should not be collected.