194 VARIATION, DISTRIBUTION, AND EVOLUTION OF THE GENUS PARTULA. 
mens were found in the lower valley, where dextral individuals are few and rubescens 
abounds, and that reversed snails increased in numbers in passing further inland. 
My own sinistral specimens are entirely typical brown affinis, and do not exhibit the 
color-characters of rubescens. How far inland their kind extends, I do not know; 
quite probably they decrease in numbers when the central basin is reached, but 
certainly they do not now exist as a large and flourishing colony in the outward part 
of the whole habitable area, so far as my threefold experience goes. 
TasB_e 127.—Partula otaheitana affinis. Papenoo Valley. 
Per cent of adult ota- 
Dextral. Sinistral. “ a 
heitana population. 
Area. pees Sie 
Adults. | Adolescents. | Adults. | Adolescents. | Dextral. | Sinistral. 
Wowerl (1906) pers 5) 3 0 0 6.66 0 
Middle (1908)....... 57 7 2 1 38.25 1.34 
Upper (1909)....... 91 19 5 0 32.73 1.79 
One further matter needs to be discussed at this point, namely, the statement 
by Garrett that Partula stolida Pease occurs in this valley at a point “about two 
miles up” lurking among fern roots. ‘This species is referred by Pilsbry to P. 
compressa ‘Pfeiffer’ Reeve. In spite of prolonged search, no specimens were 
found that conformed to the descriptions of any of these writers. Certain of the 
affinis shells, it is true, are much compressed in the last whorl, but such shells fall 
far short of the length given by Garrett. It may be that such examples are really 
abbreviated relatives of the shells named by Pease as stolida; if so, then the type 
so distinguished is only a modified affinis, for my own specimens certainly belong 
to the latter primary variety. 
TaBLE 128.—Partula otaheitana affinis. Papenoo Valley. 
MEan VALUE. 
Shell. Aperture. Length aper- 
ture + length 
shell, propor- 
Length. Width. Proportions. Length. Width. Proportions. tions. 
Series. Tooth, index 
mm. mm. p. ct. mm. mm. p. ct. p. ct. 
16.6918 .0734| 9.7145 .0368| 57.9546 .2246| 8.9981 = .0376| 6.6200 .0317| 73.4091 .1935| 53.7182 .1823| 1.3637+.0701 
16.5308+.0625| 9.7051=+.0342) 58.6410 .1521) 8.8487 +.0337| 6.6718 .0286| 75.2179 +.2163] 53.3974 .1315] 1.5595+.0712 
S—_— 
Dex., all years...| 147] 16.6235 .0462| 9.6986+.0242) 58.2143 .1266| 8.9109 .0242) 6.6442 + .0205| 74.3299 .1558] 53.4864 .1034| 1.5164+.0507 
17.1928 + .2694) 10.1571 .1435| 59.8333 .3397| 9.1285 .1138] 7.0143=.1050| 77.0714 .2303] 52.9286 .2676) 1.7143+.1784 
STANDARD DEVIATION. 
0.8067 .0519| 0.4051+.0260) 2.4703=.1588| 0.4141 + .0266| 0.3487 .0153} 2.1275 .1368] 2.0051+.1289) 0.7715+.0495 
-8185 + .0442 4483+ .0242) 1.9918.1075| .4414+.0238| .3744.0202| 2.8325+.1529| 1.7216.0930| .9679+.0503 
_—$—$—<— 
.8299 + .0327 .4342+.0171| 2.2755+.0895| .4357=.0171| .3687=.0145| 2.8003+.1102| 1.8589 .0731] .9296+.0358 
eee 
1.0568+.1905 -5628=.1015) 1.3325+.2402| .4462+.0805} .4119+.0742 9035 .1628| 1.0498 1892} .6999+.1261 
1The numbers are respectively 55, 84, 153; 7. 
