PARTULA OTAHEITANA. 187 
A further preliminary word regarding dubia is necessary. In the literature 
there is some confusion of affinis dubia Pease, with certain forms of Partula faba 
taken in the island of Tahaa, and named dubia by Garrett in manuscript; the name 
should be reserved for the subordinate form of Partula otaheitana affinis. Pilsbry, 
it is true, regards this distinctly banded type as coequal with affinis, an opinion in 
which I can not concur for reasons which will appear in the detailed description. 
Hartman, in my judgment, is entirely in error in uniting afinis with lignaria; 
the latter primary variety, as we shall see, is located far away from the territory of 
the former, and its representatives differ fundamentally in size, shape, strigation, 
and banding when this occurs. With regard to other synonyms which have been 
given as specific names to peculiar individuals, such as bacca and possibly nitens, it 
may be said that they prove to be of no real taxonomic value when a survey is made 
of all of the colonies of affinis with all of their variations. 
In earlier pages it has been stated that this primary variety, taken as a whole, 
is referable to an ancestral stock like the composite P. otaheitana otaheitana of 
Fautaua Valley, because its distinctive peculiarities, here unmixed with others, are 
displayed by some of the members of the latter subdivision. Specifically, what may 
be called the general unit-characters of affinis are as follows: 
Coil: Dextral predominating, sinistral by occasional mutation. 
Color: Various shades of light and dark brown, faintly reddish only in certain sharply restricted 
colonies. Sometimes strigated. Banded patterns of diverse types, locally restricted. 
Apex almost invariably like the larger whorls in color. 
Surface: Strigated both transversely and longitudinally; never as smooth as rubescens. 
In a word, the diagnostic qualities of affinis are precisely those which rubescens 
lacks, and vice versa, with rare exceptions inthe case of reversed coil and reddish color. 
The absolute and relative numbers of P. o. affinis in the valleys of its entire 
range have been given in table 56; the variations in numerical abundance possess 
much significance, but it is unnecessary to repeat the pertinent discussions of earlier 
pages. Additional details regarding the make-up of the several colonies are given 
in table 119. While the figures for some of the valleys are doubtless misleading on 
account of the small numbers involved, yet enough colonies are fully represented 
in the collections to provide the basis for certain definite conclusions. It is certain 
that there is considerable variation, colony by colony, in the proportionate numbers 
of dextral and sinistral snails, and in the relative abundance of the unbanded and 
banded color-forms. Further data as to variation in the relative numbers of sub- 
ordinate color-forms do not appear in this table, but they will receive due consid- 
eration later. 
Proceeding one step further, we may array the several colonies in groups of a 
secondary order, on the basis of subordinate characters. In most cases it requires 
very close study and comparison of the several localized associations in order to 
discern any differentia of real value; when discovered, they are small of necessity, 
but they are fully as significant as the wider differences exhibited by the several 
associations of P. clara and P. nodosa, and by the colonies of the otaheitana crassa 
series, later to be described. One of the subdivisions of affints, viz, erythrea, is so 
