INTRODUCTION ccxxvii 



trunks and branches of 'Pua' trees [Olea sandwichensis) and are very well concealed 

 and not very likely to be noticed unless specially sought for. 



Atnastra with loi and Lepfachatwa with 76 species are the genera most widely 

 distributed, species occurring on all the islands, though Kauai and Hawaii at either end 

 of the group are comparatively poor in species. The species of Amastra {s. s.) are 

 essentially terrestrial and found beneath and in cavities of rotten logs and tree-ferns, 

 under stones, in decayed stumps, in the hollows and crevices of hard logs, and amongst 

 decaying vegetable debris, in damp places in the forest. On Kauai (though not peculiar 

 to it) the smaller sub-genus Aviastrella is dominant. Here too are the two most re- 

 markable forms of the small sub-genus Kauaia. The species of the sub-genus Laviinella 

 are of great interest from their habits, being transitional in these between Achatinella 

 and Amastra (^s. s.'). They are largely of arboreal habits, many of them being found 

 especially on the trunks and dead branches of trees even at a considerable height; they 

 have the habit of smearing themselves with mucus, to which fragments of debris 

 become attached, so that they closely resemble the surface on which they rest. Some 

 of the species are particularly fond of Urticaceous plants and may be found on the 

 leaves of these as well as on the trunks. L. gravida is sometimes found in great 

 colonies on the fronds of soft-leaved ferns. L. depicta is abundant in the highest 

 boggy forests of IMolokai on the leaves of Astelia, above the range of other Achati- 

 nellas, and there is an allied species in similar localities on the \V. Maui mountains. 

 The small shells of the genus Leptachatina resemble those of Amastra {s. s.) in their 

 habits and are often found in company with the latter. L. arborea is common on trees 

 on Hawaii and of wide distribution, and even occurs on the leaves of JMyoporum in the 

 higher forests, above the rain-belt. 



Thaamwiia omphalodes is a remarkable development o^ Leptachatina, and apparently 

 very rare. I have never met with it. 



Carelia, containing the largest Hawaiian shells, is peculiar to Kauai, though it 

 formerly existed also on Niihau. Living specimens are now scarce, but in some parts 

 of the lower forests of Kauai many dead ones (mostly broken) were noticed, in witness 

 of their former abundance. In some of these localities they were accompanied by many 

 dead shells of Kauaia and the remains of the large weevils of the genus Rhyncogonus, 

 all species still existing, but rare. 



Of the Tornatellinidae the very minute shells of the genus Tornatellina are very 

 numerous and occur on all the islands. They were only casually collected by me and 

 are doubtless very numerous in species. Some species occur quite outside the forest, 

 at low elevations. 



Auriculella is very abundant on Oahu, species and individuals being numerous. 

 They are variable not only in colour, but in the fact that some of the species have either 

 dextral or sinistrorsal shells. Colonies of a species differ greatly in this respect, even 

 when found at no great distance from one another. Of one species a large number 

 of examples taken together had about 50 per cent, dextral and the same number 



