PARTULA OTAHEITANA. 269 
TaBLeE 223.—Partula otaheitana crassa. Numerical relations. 
Per cent p Per cent “Red” “Vellow”’ patie 
phea 
confluens. 
No. of 
adults. Sy jata, | Sit, Pheea [‘‘medium”] | [‘‘light’’] 
Division and valley. 
confluens. 
Southern crassa: 
Atitara 
Orofere 
occidentalis: 
Papehue 
Northern crassa: 
aberrans: 
Taapuna é [40.5] (11.1] 
1The bracketed figures refer to 180 perfect specimens. 
SOUTHERN CRASSA SERIES—VAITUPA TO OROFERE VALLEYS. 
VAITUPA VALLEY. 
Vaitupa is one of the series of valleys grooved in the westward slopes of the 
great triangular land-mass that lies between Temarua in Papara and Orofere in Pza. 
The main ridge of this sector, tending downward from Mount Ivirairai, reaches the 
coast at Maraa Point, at the southeastern corner of the island. Hence the line 
of contact between the area of crassa and that of sinistralis does not coincide with 
this ridge as a natural boundary, but lies between Vaitupa and Vaipuaril; the latter 
belongs geographically in the western quadrant, although its otaheitana inhabitants 
are close relatives of the southern associations. 
The snails were all sinistral in a collection of 321 adults, 37 adolescents, and 
149 embryonic young dissected out of their parents. Among the first, the color- 
classes are represented as follows: phea striata, 202, or 62.9 per cent; phza confluens, 95, 
or 29.6 per cent, cestata, 24, or 7.5 per cent. In the first division (plate 33, figs. 1 
to 5), the ground-color is yellowish brown and is crossed by narrow and distinct 
strigations, sometimes thickly crowded; decortication gives a peculiar pallid cast 
to the shell (plate 33, fig. 1). The phea confluens shells (plate 33, figs. 6 to 9) agree 
with those of the same name among s7nistralis colonies, having indistinct markings 
that in the more deeply colored examples simulate the uniform color of solida; the 
shells of figures 6 and g display abnormalities in color and lip respectively. The 
banded or cestata shells are never sharply striped (plate 33, figs. 10 to 15), and it is 
interesting to note that their ground-colors are similar to those of either striata or 
confluens. Usually only a single band is present, which corresponds in position 
with the median marking in three-banded sinzstralis, and with the lower (right) 
portion of the median zonal stripe of typical sinistrorsa examples with bands. 
More rarely, a faint sutural marking is displayed (fig. 12), while in one instance only 
(fig. 10) the second stripe is midway between the “median” one and the suture. 
The aspect of the aperture is novel, as the figures show. Where the inner 
margin of the lip sweeps upwards to the columella, there is a more or less pronounced 
nodosity, which is displayed by all shells, although it is less developed in the phea 
confluens group. 
