214 PROCEEDINGS OF THE ACADEMY OF [1895. 



DESCRIPTIONS OF NEW SPECIES OF ACHATINELLIDJE FROM THE 



HAWAIIAN ISLANDS. 



BY D. D. BALDWIN. 



At the present time the total number of described species of Acha- 

 tinella, after eliminating the Auriculella and Leptackatina, is about 

 330. Of these 102 are manifest synonyms or varieties. Some of 

 the remaining species are closely allied, and nearly all exceedingly 

 variable. 



In the past twenty years only five species have been added to the 

 list, though during this period several new regions have been explored 

 and many new forms discovered. Strange as it may appear, large 

 districts remain yet to be explored. These will require much re- 

 search, as well as considerable time before the molluscan life and its 

 exact distribution can be fully ascertained, for the habitats of the 

 Achatinella are our lofty and rugged mountains, covered with almost 

 impenetrable forest jungles, and furrowed by deep gorges, often diffi- 

 cult of access, a species being often restricted to a single isolated 

 mountain ridge or gorge. 



The inconstant and variable characters which many of the species 

 of Achatinella exhibit, the uncertainty of some of the species already 

 published, and the somewhat confused synonymy of the group, all 

 contribute to render difficult the matter of affirming new species. 

 Of great importance is the geographical position or distribution of a 

 species. Differences in the external appearance and color of the 

 animals furnish specific tests of essential value. Peculiarities in the 

 sculpturing and color of the earlier or embryonic whorls have proved 

 of value in determining some of the species. An experience also of 

 over forty years in collecting and studying the habitats and distribu- 

 tion of Achatinella may be to some extent a guarantee for the 

 validity of the new species herewith presented. 



We are indebted to Rev. Prof. Gwatkin, of Cambridge, England, 

 and Mr. H. Suter, of New Zealand, for notes regarding the lingual 

 dentition of the species of Achatinella. They indicate two very dis- 

 tinct divisions of the genus, as founded on the structure of the radula. 



