156 VARIATION, DISTRIBUTION, AND EVOLUTION OF THE GENUS PARTULA. 
The next question to present itself deals with the possible differentiation of 
the red and yellow shells in structural respects. As the relative numbers of these 
two classes are not the same in the three series compared above, it might be that 
the divergence of one subcolony from another in average qualities is due to a real 
difference in the case of yellow shells, while the red ones remain the same. Do the 
red and yellow classes really differ, and does each kind change as the observer pro- 
gresses inland? 
Tas_e 95.—Partula otaheitana rubescens, Papenoo Valley. Comparison of color-classes 
on the basis of mean values. 
SERIES OF 1906 
Character. 
Difference, yellow as 
Wu? GED: Nea! (GW) compared with red. 
Shellblensth?smimes svete cerca erertreiocre ter .4342 + .1237 .6323 = .0900 [—0.1981= .1562] 
wid ths,mm ws Weruslorseroahteverecohenk eileen ee .1737= .0635 .4726= .0533 . 2989 .0829 
DIOpOrtions, Px Ctscc ccs oats aie euehetorer ole tosieyeceioie . 3421+ .4178 .4608= .2313 .1187= .4775 
Apertureplensth smimnseareeeccieieri ieee .2790+ .0941 .5509+ .0459 — .2719+ .1047 
width mms qee eyes oats oreo ee erent . 7211+ .0934 . 8687 = .0410 — .1476= .1020] 
[OFROPOLMAKEIGL Joh Cibo 000 o0000000000000000006 . 8684+ .3696 .5785 += .3055 . 2899+ .4795] 
Length aperture + length shell, proportions, p. ct .1316+ .3592 .9902+ .1901 . 8586+ .4064 
Mooth index: Swe ectisocie eo oe ees cea sea . 7895 = .1186 8431+ .0960 0536 .1525] 
SERIES OF 1908 
Character. 
Difference, yellow as 
Yellow (21). Red (65). Comparedicithiced 
Shellblengthysmims o/c craves ccs ove sites ie ses sxserer te tererecerets 20.2976 .1772 .3577 .0717 .0601= .1911] 
width). mm'sserte: 2 eae tis eaho se Slee eer 11.0619 .0790 . 2693 = .0494 . 2074 .0931 
Proportions; ips (Ctsiys hoe eis stare etomidate 54.5952+ .3241 . 2846+ .1604 -6894= . 3616] 
Aperturejlengthssmmeseeeeeeeee eee eee eEne 10.1572 .0648 . 3031+ .0466 — .1459+ .0797] 
Wid thi ymim setaseiseorevoisce Stee ane eee ere 7.5857 .0571 . 6662 + .0402 .0805= .0698] 
KNOY fh Go ogg00000000 voeo0GdCDaNC 74.5000 .3548 . 3308+ .2262 .1692 = . 3548] 
Length aperture + length shell, proportions, p. ct 50.2143+ .2805 6384+ .1431 .4241+ . 3149] 
Tooth yind ex 4.25 csstevetevsrevovelete sicreval cere okey teeta ere ores 2.2857 .1516 . 2899 .0853 .0042 = .1739] 
(69) 
SERIES OF 1909 
Character. 
Difference, yellow as 
Yellow (65). Red (115). ait peneel SHEN HL 
Shelitlen pth yin misssae yaa oe per 3423 + .0736 2978 .0575 | [+0.0445- .0934] 
SACL ah hu linaceers camer cere Ge aoe .4108=+ .0451 2496+ .0318 .1612+ .0551 
proportionsipnctascaacrecee ee ICL EEO .1462= .2163 .2478= .1390 .8984= .2571 
Anertureylengsth mime eee ene ere . 3523+ .0443 .2687= .0317 .0836= .0544] 
Wid thm Mic ce topes arate rerorere me eons Re .6816+ .0335 . 6687+ .0270 .0129= .0430 
proportions pacts eee eer . 2231+ .2680 . 7448+ .1949 .5217+ .3314] 
Length aperture + length shell, proportions, p. ct .9151= .1587 .5608+ .1182 .3543 = .1979] 
Mooth index n 56 sv ssvenshscsrssecerere sal ses tel oneusteieheisieko toon hele -4000= .0787 .4701= .0640 .0701= .1014] 
(65) (117) 
