192 VARIATION, DISTRIBUTION, AND EVOLUTION OF THE GENUS PARTULA. 
In fecundity (table 124) the dextral classes exhibit the expected average. 
Unfortunately the reversed adults bore no young snails sufficiently advanced to be 
interesting. The light and dark classes produced contrasted young as well as their 
own kind (table 124), while all four of the embryonic snails from banded adults 
were apparently plain, and light in color. Possibly the production of markings is 
delayed in this colony. It must not be supposed that the adults of this class are 
really products of the more numerous banded stock of Tuauru, for aside from topo- 
graphical difficulties involved, a single striped adolescent, well advanced, was found 
here;. this individual must have been produced by an adult residing in Ahonu. 
Again, as regards the few sinistral snails, an origin elsewhere is not probable; even 
though all of the young of dextral adults were direct in their coil, and although the 
several adults themselves do not provide data on heredity, yet a single small sinistral 
adolescent collected in Ahonu gives positive proof that such individuals are pro- 
duced in this valley, although infrequently. 
TaBLe 124.—Partula otaheitana affinis. Ahonu Valley. 
Fecunpity. HEREDITY. 
Rec-| No. of | Per cent} No. of| No. of | Total Average | Average Young, plain. 
SELES: ords.| gravid.| gravid. | eggs. | young. |contents.| for gravid.} for all. 
Light.) Dark. 
Adults: 
Plain: 
Light. . 
Dark... 
Banded.. . 
Dex., plain... 
Dex iallerenicne 
Sin., plain.... 
Faaripoo VALLEY. 
In this narrow gully, not far from Papenoo, cleft in the triangular land-mass 
to the west of that great valley, a flourishing colony of afinis was found, although 
the associated rubescens was very sparsely represented, as noted earlier. The 
general composition of this colony is much like that of Tuauru, with two exceptions: 
reversed individuals are absent and banded shells are few, asin Ahonu. ‘The last- 
named (plate 28, figs. 48 and 49) display three well-marked stripes, viz, the basal, the 
median, and the subsutural, the last of which was rarely exhibited by shells of the 
north. The light and dark classes (plate 28, figs. 46 and 47, unusual types) differ dis- 
tinctly in several of the statistical characters (table 125). “The members of the 
small banded group agree sometimes with the one and sometimes with the other 
class of unstriped shells. 
The fecundity of all classes is high (table 126), with substantial agreement. 
In the matter of heredity (table 126) it is interesting to find that the plain and 
banded groups breed true to their respective types. Yet here, too, the latter are to 
be regarded as genetically allied to the former, and not as stragglers from near-by 
valleys. Ahonu to the west is well separated topographically, while the next 
valley to the east where banded snails occur is Farapa, on the other side of Papenoo, 
in which none of this type were taken. 
