200 VARIATION, DISTRIBUTION, AND EVOLUTION OF THE GENUS PARTULA. 
The shells of this colony are individually and collectively of astonishingly small 
size, as shown by the illustrations and the statistics (table 133). It is noteworthy 
that the banded shells differ from the rest in very much the same ways as in the 
Farapa association. 
Fecundity (table 134) is lower than heretofore; the eggs outnumber the ad- 
vanced young, thus proving that reproductive activity had recently been resumed. 
The numbers of plain and banded young agree exactly with those of the corre- 
sponding groups of gravid adults (table 134), not because the two types breed true, 
but because complementary contributions are made by each class to the other one. 
TIAREI VALLEY. 
The small collection from Tiarei is interesting on account of its general agree- 
ment with the Faarumai series. The banded shells are more numerous relatively, 
and resemble the Farapa types with suffusion on the body whorl. One specimen 
(plate 29, fig. 37) exhibits only a partial clouding near the suture. In size (table 
135) the shells are collectively small, but their colonial averages slightly exceed 
those of the preceding valley. 
TasLe 135.—Partula otaheitana afinis. Tiarei Valley. 
Mean VALUE. 
Aperture. Length aper- 
ture + length 
shell, propor- Tooth, index. 
Series. 
Proportions. Length. Width. Proportions. 
16.1923+.0418) 9.2882+.0232| 57.1445+.1189} 8.3504+ .0225) 6.3563+.0185| 76.0630+.1310) 51.4186+ .0961) 2.4593 + .0493 
16.4750+.1004| 9.4125+.0519| 57.1250 .2788} 8.5125+.0526| 6.4500+ .0484) 75.8125 .5647| 51.6250+.2590) 2.5625+.1177 
16.2222 .0377| 9.3013+.0200) 57.1424 .1104} 8.3675+.0211| 6.3662+.0174| 76.0364 .1316] 51.4404+ .0903| 2.4702+ 0459 
STANDARD DEVIATION. 
0.7202+.0295| 0.3974 .0164) 2.0493+.0831] 0.3878+ .0159| 0.3189+.0131) 2.2562+.0989) 1.6558+.0679) 0.8499 .0348 
.5953+.0710| .3079+.0367) 1.6536+.1971| .3120+.0371| .2872+.0342) 3.3488+.3993} 1.5360+.1831) .7043+.0812 
-6865 + .0267 .3649+ 0141} 2.0115+.0781) .3836+.0149} .3170+.0123} 2.3969+.0931| 1.6448+.0639| .8363=+.0324 
Fecundity (table 136) is average. The figures for heredity (table 136) show a 
slight excess of plain young. 
TaBLe 136.—Partula otaheitana affinis. Tiarei Valley. 
FEcuNDITY. HeERepITy. 
No. of | Percent! No. of | No. of | Total | Average | Average 
gravid.| gravid. | eggs. | young. jcontents.|for gravid.| for all. 
plainer 132 114 86.3 192 80 272 2.39 2.06 
Banded... 16 12 75.0 15 13 28 2.33 ih 5) iW oo00 78 2 80 
Young,| Young, 
plain. |banded. fioval: 
Series. | Records. 
ocd0c : 300 2.38 
