290 VARIATION, DISTRIBUTION, AND EVOLUTION OF THE GENUS PARTULA. 
specimens resemble certain members of the Taapuna aberrans division of the crassa 
series. In brief, then, it appears that the primary variety /ignaria is not uniform 
in its group-composition throughout the extent of the single valley that it inhabits. 
Turning now to the statistical analysis of the material, we may deal first 
with the data relating to the 1906 series (table 244) from the lower valley. Without 
enumerating all of the details, it may be pointed out that the several color-classes 
in each of the “plain” and the “banded”’ sections differ inter se, in some cases to 
significant degrees. The narrower form of the shells in the case of the dark-banded 
division is an illustrative instance. 
TasLe 245.—Partula otaheitana lignaria, Tipaerui Valley. Comparison of annual series. 
Mean VALUE. 
Shell. Aperture. Length aper- 
ture +length 
shell, propor- 
Length. Width. Proportions. Length. Width. Proportions. tions. 
Series. 
mm. mm, p. ct. mm. mm. p. ct. p. ct. 
Plain, 1906, dex... 17.8767 + .0276| 10.4447 +.0142) 58.3519+ .0692) 9.4709+ .0144| 7.4660+. 78.8228+ .0864) 52.8689+.0652 
Banded, 1906, dex. | 17.9505+ .0386} 10.5020+ .0193) 58.4554+.1051) 9.4356+.0198) 7.4158+. 78.6337 .1169) 52.4257+.0899 
Plain, 1907, dex... 18.0253+ .0674| 10.3986 .0323) 57.4041 .1580} 9.4014 .0340) 7.3877=. 78.6233 .1960) 52.0479+ .1437 
Banded, 1907, dex. 17.9942 + .0837| 10.4674+ .0310) 58.1047 + .2094| 9.4860 .0412) 7.4349=+. 78.4535 °2440) 52.6163+.1707 
Plain, 1909, dex... 18.3099 + .0478) 10.4620+ .0258) 57.0845+.1355] 9.5225+.0274) 7.4254+. 79.0000 .1766) 51.9648 .1145 
Banded, 1909, dex. 18.4308 + .1093) 10.6000+ .0499) 57.4615+ .3310} 9.6154+ .0493) 7.5846+. 78.6923 .4067) 52.2692+.2496 
All, 1906, dex 17.9010+ .0224) 10.4635 .0105) 58.3860 .0579) 9.4593+.0117) 7.4495+. 78.7606 .0704| 52.7231+.0532 
All, 1907, dex 18.0138+.0526| 10.4241 + .0235) 57.2155+.1271) 9.4328+.0264| 7.4052+. 78.5603 .1530) 52.2586+.1117 
All, 1909, dex | 18.3286 .0438} 10.4833+ .0233) 57.1429 .1257| 9.5369+.0245| 7.4500+. 78.1071 .1628) 52.0119+.1044 
INV, G25 co 0000800 17.9955 + .0180} 10.4621+.0091) 58.0757+.0475) 9.4704+ .0093) 7.4439+. 78.6125 .0570) 52.5301 .0419 
Plain, 1909, sin.... | 18.2300 .1065} 10.6700=+ .0558) 58.5000+ .2336) 9.7100+ .0613) 7.5800+. 78.1500 .4138) 53.0500+ .2104 
Banded, 1909, sin.. 18.4250+.1806| 10.7500 .1536| 58.2500+ .4988) 9.7000+ .0954| 7.6000+. 78.7500 1.0496) 52.5000 .0 
Tooth, index. 
3.3437 + .0259 
3.4581 + .0373 
3.2432 + .0680 
3.2558+.0591 
3.2905 + .0448 
3.1154 .0923 
3.3810 + .0213 
3.2479 + .0482 
3.2644 .0396 
3.3417 + .0176 
3.2000= .1128 
3.5000 + .3770 
All, 1909, sin | 18.2633 .0942| 10.6833+ .0533) 58.4583 .2121) 9.7082+ .0536| 7.5833+. 78.2500 .3899) 52.9583 .1776| 3.2500+.1070 
STANDARD DEVIATION. 
Plain, 1906, dex... 0.8216+.0195) 0.4293+. 2.0832 + .0489) 0.4352+ .0102| 0.3585+.0084) 2.6013=+ . 1.9681+ .0461 
Banded, 1906, dex. -8280+ .0273 4073+. 2.2145+.0743) .4169+.0140) .3541+.0119} 2.4629> . 1.8956 + .0636 
Plain, 1907, dex... -8539 + .0476 4096+. 2.0011 .1117) .4305+.0240) .2969+.0165) 2.4825=+ . 1.8207 + .1025 
Banded, 1907, dex. -8139 = .0592 3017+. 2.0361 .1481) .4009+.0291) .2786+.0202) 2.3718= . 1.6595 + .1207 
Plain, 1909, dex... -8449 = .0338 4565+. 2.3949 .0958) .4847+.0194| .4190+.0167| 3.1211=+ . 2.0233 + .0809 
Banded, 1909, dex. .8260+ .0773 3772+. 2.5035 + .2340) .3728+.0348) .2891+.0270) 3.0145=+ . 1.8873 .1765 
0.7854=+ .0183 
-7890 = .0264 
-8669 + .0481 
5743+ .0418 
-8075 + .0317 
-6976 = .0653 
All, 1906, dex -8244 + .0158 4231+. 2.1278+.0409| .4296+.0827| .3578+.0069| 2.5882= . 1.9556+ .0376 
All, 1907, dex -8394+ .0372 3747+. 2.0291 .0899) .4217+.0187| .2906+.0129) 2.4434= . 1.7841 + .0790 
All, 1909, dex..... -8425 + .0310 A479. 2.4159 .0889) .4704.0173) .4057+.0149) 3.1282= . 2.0056 .0738 
All, dex -8460 + .0127 4223+. 2.2269 + .0336) .4378+.0066| .3599+.0054) 2.6739= . 1.9658 + .0296 
Plain, 1909, sin.... -7061 + .0754 3702+. 1.5491 .1652| .4073+.0433) .3815+.0407} 2.7436+ . 1.3955 + .1488 
Banded, 1909, sin.. 5356+ .1277 SSS. 1.4790 .3527| .2828+.0674| .4123+.0983) 3.1124+ . 0 
All, 1909, sin...... -6842+ .0666) .3869=. 1.5405 .1500) .3894.0379| .3891+.0379| 2.8321= . 1.2900+ .1256 
A more interesting general result follows from the comparison of the several 
annual series (table 245). With remarkable consistence the shells become larger 
on the average as we ascend the valley. Still more regular are the progressive 
changes in proportionate measures. Jn all three cases, a decrease in the figures 1s 
found. ‘The short series of 1909 sinistral shells agrees on the whole with the dextral 
group of the same locality and year. 
.7885 + .0151 
-7724+ .0341 
-7945 + .0280 
.7896 + .0124 
-7483 + .0798 
1.1180 .2665 
.7772 + .0756 
