and smooth. The embryonic whorls are not flattened. The outer lip is thin or only slightly thickened within the apex but not expanded. These are the most generally distributed of the Achatinella species and show a prolific area of intergrading color patterns. Type species of the subgenus Achatinellastrum is Achatinella stewartii (Green, 1827). Ecology Habitat These snails live in trees. Currently they are only found in mountainous dry to moist forests and shrublands above . Most individuals spend their entire life on just one tree. Feeding These tree snails are nocturnal, and feed by grazing fungus which grows on the surface of native plant leaves. Although these tree snails are occasionally found on introduced plants, it is unknown whether or not the fungus which grows on these plants can provide long-term support for healthy breeding populations of these snails. In captivity Achatinella feed on fungus growing on leaves of Metrosideros polymorpha. They also feed on cornstarch, which can be spread in terraria with water and on cultures of sooty mold grown on laboratory agar. In captivity, cuttlebone is used as a source for calcium. Life cycle Adult snails are hermaphroditic (having both male and female reproductive organs) and can live for many years. These are live bearing snails (give birth to live snails instead of laying eggs). Predation and other threats Because growth rate and fertility are very low, these snails are especially vulnerable to loss of individuals through human collection, through predation, or because of other disturbances. The most serious threats to the survival of Oʻahu tree snails are predation by the introduced carnivorous snail Euglandina rosea, predation by rats (Rattus exulans, Rattus norvegicus, Rattus rattus), and loss of habitat due to the spread of non-native vegetation into higher elevation forests. Jackson's chameleon Trioceros jacksonii, that was introduced to Hawaii in early 1970s, is a serious threat to Achatinella, because it directly preys on them and on other snails too. Other predators of Achatinella include the land planarian Platydemus manokwari. Predators of Achatinella: Hawaiian folklore According to Ancient Hawaiian folklore, the kāhuli are known as the pūpū kani oe, which translates to "shell that sounds long" or the "singing shell". They are believed to be able vocalize and sing at night. Experts have attributed this association to the chirping of crickets at night when the snails are active. Native Hawaiians used the shells of the snails to create kahuli