PARTULA NODOSA. IOI 
The statistical characters (table 47) show how greatly this small series differs 
from previously described colonies. ‘The tooth is present in every shell (table 47). 
All four were gravid (table 47), and together they bore 6 plain brown and dextral 
young, besides 4 eggs; the absence of sinistral young is negative, but competent 
evidence that these snails are not dextral and otherwise modified sports produced 
by the plain sinistral P. otaheitana of this valley. 
Partula nodosa intermedia var. nov.—Papehue Valley. 
In the three remaining valleys of the range of nodosa the shells resemble var. 
composita of the north, but in some respects depart in the direction of the Atehi 
association. ‘The varietal name intermedia is therefore chosen for these southern 
colonies, of which the one existing in Aoua Valley is the most characteristic. 
Papehue Valley (plate 150) lies about 0.75 mile to the south of Atehi, to which 
itis parallel. It is much larger than the latter, but its broken and rugged topo- 
graphical features are similar. ‘The first snails were found at a distance of 1 mile 
from the coast, and from this point inward to a limit of 3 miles. In 1906 this 
entire area was investigated, and in 1907 the outer part was revisited; the area 
of collection in the first year thus included that of the second, together with the 
remoter and higher part of the valley. All of the snails secured were dextral. 
Two classes only can be distinguished 
here, namely, “plain” and “banded” shells. 1906 1907 
The latter (figs. 19 to =f. plate 24) conform Adults. | Per cent. | Adults. | Per cent. 
to the typical Class IT shells of Taapuna ani a ey Es age - ae 
Punaruu (var. composita, color-form trilineata) | Banded..| 60 52.6 42 43.7 
and they differ from the majority of the 
banded individuals of the intervening colony in Maruapoo Valley. No exact 
counterparts of Class III (var. composita, color-form confluens) occur, but some 
(fig. 23) display considerable suffusion between the subsutural and median 
stripes, and are thus transitional to Class III. The “plain” shells (figs. 11 to 18, 
plate 24) are evenly colored as a rule. A few exhibit ill-defined strigations which 
never attain the distinctness of similar markings in Class I shells of var. composita 
from Punaruu. In color they range from light brown through intermediate shades 
to dark brown and solid purplish-brown, with the white sutural area more or less 
sharply defined in the majority. Some of these last resemble many of the plain 
shells from Maruapoo, but the direction of their coil is exactly opposite. 
Certain members of both classes have the nodosity on the columella border 
greatly reduced (figs. 11 and 19, plate 24). “They are the smaller in size, and the plain 
ones among them resemble the Atehi shells so closely as to dispel all doubts as to 
the morphological relationship between the peculiar Atehi specimens and the Aoua 
association. The relative numbers in the two distinguishable classes differ in the 
two annual series. 
The journey of 1906 extended into the deeper parts of the valley and covered 
the ground of 1907, together with the higher regions. It follows that the first series 
includes representatives of the second year’s area of collection, as well as snails 
