A Field Guide to the Snails of Lord Howe Island

9 Shell sculpture is an important feature in many groups. The shell whorls are divided into two regions, the protoconch or embryonic whorls (developed before the baby snail hatches and usually comprising the first 1-2 whorls), and the teleoconch or adult whorls.These can be distinguished by a change in sculpture. Both the protoconch and teleoconch can be sculptured with the following elements singly or in combination: radial ribs, lirae or threads; spiral cords or grooves; or pits. Radial and spiral sculpture can intersect to form patterns that are decussate (crossing to form an ‘x’) or reticulate (resembling a net). Incised spiral grooves (protoconch) Incised spiral grooves (teleoconch) Radial ribs Spiral lirae Radial ribs, reticulate microsculpture Radial ribs, microspiral lirae