256 VARIATION, DISTRIBUTION, AND EVOLUTION OF THE GENUS PARTULA. 
The material from these two localities, as well as that from Opiriroa, has not 
the value of a long series taken in a valley like Moaroa, but it is interesting on 
account of its demonstration that local variations in size, etc., can be found in series 
taken from places very near one another. In another way it is important, inasmuch 
as the banded class includes two somewhat novel kinds of color-variants, which 
become even more numerous farther west; hence the area in which the newer forms 
occur is transitional from that of previously described sinistralis associations. 
As indicated in table 196, apex is absent from all three series. The unbanded 
shells are almost all true confluens (plate 32, figs. 23 and 24), although some vaguely 
strigated individuals occur, which, nevertheless, fall short of the distinctive striata 
type. The banded shells fall into three subdivisions, as follows: (a) basal band 
light, sutural band and median band distinct up to the last whorl, when the latter 
fades out (plate 32, figs. 25 and 26); (b) all three bands continued throughout the 
basal whorl (plate 32, figs. 27 and 28); (c) with suffusion of the bands over the last 
whorl (plate 32, figs. 29 to 31). The spires of all three types are almost exactly the 
same in appearance. It is true that among sznistrorsa shells we have seen some 
with the great amount of suffusion on the last whorl, but this is the first area where 
a distinct subclass with this character can be recognized. 
TaBLeE 203.—Partula otaheitana sintstralis. 
Vaipoo, Tearatapu, and Opiriroa Valleys. 
MEAN VALUE. 
Shell. Aperture. Length aper- 
; ture + length : 
Series. No. shell, propor: Tooth, index. 
Length. Width. Proportions. Length. Width. Proportions. tions. 
mm. mm. p. ct. mm. mm. Pp. ct. Dp. ct. 
Vaipoo, unbanded..... 12) 17.2750 .1677| 9.6167 + .1023| 55.7500 .3476) 8.8667 +.1005| 6.6834 .0538, 75.3334 .4193| 51.1666+.3756| 2.8462+.1920 
bandedmemneircr 49) 16.9480+ .0669) 9.6796+ .0342| 57.0918+.2244) 8.8551+.0366| 6.7245+.0320) 75.8469 .2637| 52.2349=+.1637| 2.9184+.0950 
Wie, AMocosogo0cec. 61) 17.0123+.0641| 9.6672+.0341] 56.8279 .1982| 8.8574 .0354| 6.7164+.0278| 75.7459 .2280| 52.0246+.1553) 2.9033+.0852 
Tearatapu, unbanded..| 15 16.7100+.1060} 9.7000=+ .0623) 58.0334 .2688) 8.9133 .0799) 6.8467 + .0642| 76.7000 .4460) 53.3000+.2928) 3.0666 .1184 
banded....| 15) 16.6900 .1916] 9.7133 .0903) 58.3667 +.4490) 8.8467 +.1196) 6.8467 .0885) 77.5666+.2877| 53.0334 .3357| 2.8000+ .1303 
mMearatapuwallervrerneerrs 30] 16.7000 .1096) 9.7067 = .0530} 58.2000 + .2625| 8.8800 .0720) 6.8467 += .0547| 77.1333 .2707| 53.1667 + .2233) 2.9333=.0895 
Opiriroa, unbanded....| 40) 18.1850-+.0988| 9.8550+.0388] 54.0000 .2336| 9.1850+.0522| 6.9800 .0412) 75.6250 .3009| 50.4000 .1407| 3.1750-.0787 
banded...... 112) 18.2214 .0442) 9.9982+ .0241| 54.7857 + .1279| 9.2590+ .0253) 7.0715=+.0200) 76.3214 .1610) 50.7143 .1023) 2.8929 .0453 
Opiriroavallaneyeaes 162| 18.2118-.0417| 9.9605 + .0208) 54.5789 .1141| 9.2395 + .0232| 7.0474 .0184| 76.1382 .1436| 50.6316+.0843] 2.9671+.0399 
STANDARD DEVIATION. 
Vaipoo, unbanded..... 12) 0.8613+.1186] 0.5257+.0723) 1.7853==.2458) 0.5163+.0711) 0.2764 .0380) 2.1538=.2965) 1.9293+.2656] 1.0263 .1358 
banded....... 49] .6947+.0473| .3551+.0242| 2.3292+.1587| .3796+.0259| .3323.0226| 2.7371.1865| 1.6994+.1157| .9864-+.0672 
Waipoomallevrrerirericict: 61 7419+ .0453} .3953+.0241) 2.2955+.1401) .4099+.0250) .3224+.0196) 2.6405+=.1612} 1.7980+.1098) .9953+.0602 
Tearatapu, unbanded..| 15| .6086+.0749|  .3578-+.0440| 1.5434+.1901] .4588+.0565| .3686+.0454} 2.5612+.3154) 1.6812++.2070| .6798+.0837 
banded....| 15} 1.1002+.1355} .5188+.0638) 2.5785+.3175| .6869+.0846) .5084+.0626) 1.6519+.2034) 1.9276+.2374| .7483+.0921 
Mearatapusallyeseerrt ts mO .8905+.0775| .4468+.0375| 2.1315=.1856) .5850+.0509} .4440+.0387| 2.1982+=.1914) 1.8135+.1579| .7272+.0633 
Opiriroa, unbanded....| 40 .9269+.0699) .3646+.0274; 2.1909=.1652) .4896+=.0369} .3868=.0291) 2.8212=.2128) 1.3191+.0995| .7378=+.0556 
band edema 112 6940+ .0312) .3789+.0170) 2.0063 .0904| .3974+.0179| .3138+.0141) 2.5256+.1138) 1.6059+.0723) .7116+.0320 
Oye, All, Gq0000006 162 7624+ .0295| .3804+.0147| 2.0854+.0807) .4250+.0164) .3368+.0130) 2.6246+=.1015} 1.5419+.0596) .7292+.0282 
