296 FAUNA HAWAITENSIS 
Fam. ACHATINE LLIDAE, 
The various species of this family form probably one of the most puzzling groups 
of land-shells known: numerous ‘species’ have been described, founded almost entirely 
on shell colouration or banding, and this, bearing in mind such protean forms as Tachea 
nemoralis or Polymita picta, is a course which often leads to endless trouble. At present, 
such genera as Achatinella s.s. and Achatinellastrum are in utter confusion, and any 
attempt at a list of species simply reflects the general view of the writer and cannot be 
regarded as authoritative. 
Of recent years some species have been described, based on shell-colouration com- 
bined with that of the mantle, but it should be remembered that some malacological 
characteristics are frequently as liable to variation as are conchological ones. The 
severance of species by consideration of habitat is, again, not a necessarily certain 
guide, since one species of mollusc may range widely, while at different points of its 
range, local variations may occur. 
The history of the Achatinellidae in literature commences with Dixon’s description 
of Turbo apexfulva ; subsequently stray species were described by various authors, but 
no serious attempts were made at their study until about 1850-60, when Newcomb and 
Pfeiffer added greatly to our knowledge. To Mr Gulick, in 1858, we owe large addi- 
tions to the catalogue—so far as names go—but his views of species were somewhat 
too narrow, and he described many trifling variations as species, mainly on the ground 
of geographical range. Later, Pease did useful work and gave a catalogue of the family. 
Dr Hartman, in 1888, listed the known forms in a similar way. Of recent years Mr 
Baldwin has done the chief work on the group, and his very valuable catalogue has been 
of great assistance. 
Numerous genera and sections have been described, almost all on purely concho- 
logical grounds, and so variable are the forms that linking species are easily found. 
Still they prove useful in the arrangement of species and therefore have been admitted 
in this work. | 
A list of them arranged in chronological order may be of use. 
1828. Achatinella Swainson, Q. J. Sci. Lit. and Arts, p. 81. 
1847. Leptachatina Gould, P. Boston Soc. 1. p. 201. 
1854. Partulina Pfeiffer, Malak. Blatt. 1 p. 114. 
1854. Newcoméca Pfeiffer, ¢. c. p. 117. 
1854. Bulimella Pfeiffer, 4 ¢c. p. 119. 
1854. Lamenella Pfeiffer, ¢. c. p. 126. 
1854. <Achatinellastrum Pfeiffer, 4. ¢c. p. 133. 
1854. Ladbzella Pfeiffer, 2. ¢. p. 142. 
