The Hawaiian archipelago is the most isolated archipelago on Earth. Stretching 2500 km across the Central Pacific it is 3500 km from the nearest continental land mass. This isolation has contributed to the evolution of a unique terrestrial ecosystem comprised mostly of endemic species. So vast is the area of the archipelago and so high is the rate of endemicity that there is no other place on earth like it.
In spite of its isolation over millions of years representative species of 14 families of terrestrial and freshwater snails reached the islands evolving into an endemic fauna of at least 749 described species, 345 described subspecies of those species and one endemic family. Of those 14 families, two currently stand out as being extraordinarily successful, the Amastridae with 293 species and the Achatinellidae with 231 species. The whole diversity of the archipelago's land snails is figured on 186 full-color plates, showing 3117 images and 363 distribution maps.