INTRODUCTION. IX 



An entirely satisfactory classification of the genera is nat- 

 urally not to be expected until we are acquainted with their 

 soft anatomy. Elasmias, Tornatellina and Tornatellides are 

 viviparous, Tornatettaria, Oulickia and Auriculella being 

 oviparous. The mode of reproduction probably indicates real 

 affinity between the last three genera, especially as there are 

 other features of likeness. All of them are confined to the 

 Hawaiian group. They seem to be arboreal and terrestrial 

 adaptations of an old indigenous stock. 



Elasmias has a rather primitive, infantile aspect, resem- 

 bling the embryonic stage of other genera, as noted on page 

 114. The two genera having the axis perforate, Tornatellides 

 and Tornatellaria, are probably not closely related, though 

 superficially similar. 



Auriculella has the shell-axis solid, though often the last 

 whorl deviates, leaving a shallow umbilicus. Its special fea- 

 tures are those adaptive characters common to arboreal land 

 snails of many families varied coloring, spreading lip and 

 smooth surface. It seems significant that the Auriculella- 

 Gulickia-Tornatellaria group, like the Achatinellida, does not 

 occur on Kauai. Both groups are exclusively Hawaiian, both 

 are confined to humid forest regions, and their distribution 

 seems to have been controlled by the same conditions. 



DISTRIBUTION OF TORNATELLINHXE. 



This family is almost wholly confined to the islands of the 

 Pacific, but a few species occur in the East Indies and as far 

 west as Mauritius (1 genus). Eastward, a few inhabit the 

 American islands Juan Fernandez, Masafuera and the Gala- 

 pagos (2 genera). The Bonin Islands and islands of Izu, 

 Japan, are the northern limit (3 genera), and New Zealand 

 (2 genera) the southern. The total range lies between 34 N. 

 and 40 S. latitude, and from 80 W. longitude westward to 

 about 60 E. 



Tornatellina, Tornatellides and Elasmias are the most 

 widely distributed genera. Lamellovum is restricted to the 

 single island of Rapa. Auriculella, Gulickia and Tornatel- 

 laria are solely Hawaiian, where they have exactly the dis- 



